In Europe, and other regions using the ISO 216 paper sizing system, the weight is expressed in grammes per square metre (g/m2 or usually just g) of the paper. Printing paper is generally between 60 g and 120 g. Anything heavier than 160 g is considered card. The weight of a ream therefore depends on the dimensions of the paper and its thickness.


Most commercial paper sold in North America is cut to standard paper sizes based on customary units and is defined by the length and width of a sheet of paper.


The ISO 216 system used in most other countries is based on the surface area of a sheet of paper, not on a sheet's width and length. It was first adopted in Germany in 1922 and generally spread as nations adopted the metric system. The largest standard size paper is A0 (A zero), measuring one square meter (approx. 1189 × 841 mm). Two sheets of A1, placed upright side by side fit exactly into one sheet of A0 laid on its side. Similarly, two sheets of A2 fit into one sheet of A1 and so forth. Common sizes used in the office and the home are A4 and A3 (A3 is the size of two A4 sheets).


The density of paper ranges from 250 kg/m3 (16 lb/cu ft) for tissue paper to 1,500 kg/m3 (94 lb/cu ft) for some speciality paper. Printing paper is about 800 kg/m3 (50 lb/cu ft).


Much of the early paper made from wood pulp contained significant amounts of alum, a variety of aluminium sulfate salts that is significantly acidic. Alum was added to paper to assist in sizing, making it somewhat water resistant so that inks did not "run" or spread uncontrollably. Early papermakers did not realize that the alum they added liberally to cure almost every problem encountered in making their product would eventually be detrimental. The cellulose fibres that make up paper are hydrolyzed by acid, and the presence of alum would eventually degrade the fibres until the paper disintegrated in a process that has come to be known as "slow fire". Documents written on rag paper were significantly more stable. The use of non-acidic additives to make paper is becoming more prevalent, and the stability of these papers is less of an issue.


Paper made from mechanical pulp contains significant amounts of lignin, a major component in wood. In the presence of light and oxygen, lignin reacts to give yellow materials, which is why newsprint and other mechanical paper yellows with age. Paper made from bleached kraft or sulfite pulps does not contain significant amounts of lignin and is therefore better suited for books, documents and other applications where whiteness of the paper is essential.


Paper made from wood pulp is not necessarily less durable than a rag paper. The ageing behavior of a paper is determined by its manufacture, not the original source of the fibres. Furthermore, tests sponsored by the Library of Congress prove that all paper is at risk of acid decay, because cellulose itself produces formic, acetic, lactic and oxalic acids.


Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.


Worldwide consumption of paper has risen by 400% in the past 40 years leading to increase in deforestation, with 35% of harvested trees being used for paper manufacture. Most paper companies also plant trees to help regrow forests. Logging of old growth forests accounts for less than 10% of wood pulp, but is one of the most controversial issues.


Paper waste accounts for up to 40% of total waste produced in the United States each year, which adds up to 71.6 million tons of paper waste per year in the United States alone. The average office worker in the US prints 31 pages every day. Americans also use on the order of 16 billion paper cups per year.


Conventional bleaching of wood pulp using elemental chlorine produces and releases into the environment large amounts of chlorinated organic compounds, including chlorinated dioxins. Dioxins are recognized as a persistent environmental pollutant, regulated internationally by the Stockholm Convention on Persistent Organic Pollutants. Dioxins are highly toxic, and health effects on humans include reproductive, developmental, immune and hormonal problems. They are known to be carcinogenic. Over 90% of human exposure is through food, primarily meat, dairy, fish and shellfish, as dioxins accumulate in the food chain in the fatty tissue of animals.


Some manufacturers have started using a new, significantly more environmentally friendly alternative to expanded plastic packaging. Made out of paper, and known commercially as paperfoam, the new packaging has very similar mechanical properties to some expanded plastic packaging, but is biodegradable and can also be recycled with ordinary paper.


With increasing environmental concerns about synthetic coatings (such as PFOA) and the higher prices of hydrocarbon based petrochemicals, there is a focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags.


Adult contemporary music (AC) is a style of music, ranging from 1960s vocal and 1970s soft rock music to predominantly ballad-heavy music of the present day, with varying degrees of easy listening, pop, soul, rhythm and blues, quiet storm, and rock influence. Adult contemporary is rather a continuation of the easy listening and soft rock style that became popular in the 1960s and 1970s with some adjustments that reflect the evolution of pop/rock music.


Adult contemporary tends to have lush, soothing and highly polished qualities where emphasis on melody and harmonies is accentuated. It is usually melodic enough to get a listener's attention, and is inoffensive and pleasurable enough to work well as background music. Like most of pop music, its songs tend to be written in a basic format employing a verse–chorus structure.


Adult contemporary is heavy on romantic sentimental ballads which mostly use acoustic instruments (though bass guitar is usually used) such as acoustic guitars, pianos, saxophones, and sometimes an orchestral set. The electric guitars are normally faint and high-pitched. However, recent adult contemporary music may usually feature synthesizers (and other electronics, such as drum machines).


AC radio stations may play mainstream music, but they will exclude hip hop, dance tracks, hard rock, and some forms of teen pop, as they are less popular amongst the target demographic of these radio stations, which is intended for an adult audience. AC radio often targets the 25–44 age group, the demographic that has received the most attention from advertisers since the 1960s. A common practice in recent years is that many adult contemporary stations play less newer music because they also give ample airtime to hits of the past, so the de-emphasis on new songs slows the progression of the AC chart.


Over the years, AC has spawned subgenres including "hot AC", "soft AC" (also known as "lite AC"), "urban AC", "rhythmic AC", and "Christian AC" (a softer type of contemporary Christian music). Some stations play only "hot AC", "soft AC", or only one of the variety of subgenres. Therefore, it is not usually considered a specific genre of music; it is merely an assemblage of selected tracks from musicians of many different genres.


Adult contemporary traces its roots to the 1960s easy listening format, which adopted a 70-80% instrumental - 20-30% vocal mix. A few offered 90% instrumentals, and a handful were entirely instrumental. The easy listening format, as it was first known, was born of a desire by some radio stations in the late 1950s and early 1960s to continue playing current hit songs but distinguish themselves from being branded as "rock and roll" stations. Billboard first published the Easy Listening chart July 17, 1961, with 20 songs; the first number one was "Boll Weevil Song" by Brook Benton. The chart described itself as "not too far out in either direction".


Initially, the vocalists consisted of artists such as Frank Sinatra, Doris Day, Johnny Mathis, Connie Francis, Nat King Cole, Perry Como, and others. The custom recordings were usually instrumental versions of current or recent rock and roll or pop hit songs, a move intended to give the stations more mass appeal without selling out. Some stations would also occasionally play earlier big band-era recordings from the 1940s and early 1950s.


After 1965, differences between the Hot 100 chart and the Easy Listening chart became more pronounced. Better reflecting what middle of the road stations were actually playing, the composition of the chart changed dramatically. As rock music continued to harden, there was much less crossover between the Hot 100 and Easy Listening chart than there had been in the early half of the 1960s. Roger Miller, Barbra Streisand and Bobby Vinton were among the chart's most popular performers.


One big impetus for the development of the AC radio format was that, when rock and roll music first became popular in the mid-1950s, many more conservative radio stations wanted to continue to play current hit songs while shying away from rock. These middle of the road (or "MOR") stations also frequently included older, pre-rock-era adult standards and big band titles to further appeal to adult listeners who had grown up with those songs.


Another big impetus for the evolution of the AC radio format was the popularity of easy listening or "beautiful music" stations, stations with music specifically designed to be purely ambient. Whereas most easy listening music was instrumental, created by relatively unknown artists, and rarely purchased, AC was an attempt to create a similar "lite" format by choosing certain tracks (both hit singles and album cuts) of popular artists.


Hard rock had been established as a mainstream genre by 1965. From the end of the 1960s, it became common to divide mainstream rock music into soft and hard rock, with both emerging as major radio formats in the US. Soft rock was often derived from folk rock, using acoustic instruments and putting more emphasis on melody and harmonies. Major artists included Barbra Streisand, Carole King, Cat Stevens, James Taylor and Bread.


The Hot 100 and Easy Listening charts became more similar again toward the end of the 1960s and into the early and mid-1970s, when the texture of much of the music played on Top 40 radio once more began to soften. The adult contemporary format began evolving into the sound that later defined it, with rock-oriented acts as Chicago, The Eagles, and Elton John becoming associated with the format.


Soft rock reached its commercial peak in the mid-to-late 1970s with acts such as Toto, England Dan & John Ford Coley, Air Supply, Seals and Crofts, America and the reformed Fleetwood Mac, whose Rumours (1977) was the best-selling album of the decade. By 1977, some radio stations, like New York's WTFM and NBC-owned WYNY, had switched to an all-soft rock format. By the 1980s, tastes had changed and radio formats reflected this change, including musical artists such as Journey. Walter Sabo and his team at NBC brought in major personalities from the AM Band to the FM Band taking the format from a background to a foreground listening experience. The addition of major radio stars such as Dan Daniel, Steve O'Brien, Dick Summers, Don Bleu and Tom Parker made it possible to fully monetize the format and provide the foundation for financial success enjoyed to this day


Radio stations played Top 40 hits regardless of genre; although, most were in the same genre until the mid-1970s when different forms of popular music started to target different demographic groups, such as disco vs. hard rock. This evolved into specialized radio stations that played specific genres of music, and generally followed the evolution of artists in those genres.


By the early 1970s, softer songs by artists like The Carpenters, Anne Murray, John Denver, Barry Manilow, and even Streisand, began to be played more often on "Top 40" radio and others were added to the mix on many AC stations. Also, some of these stations even played softer songs by Elvis Presley, Linda Ronstadt, Elton John, Rod Stewart, Billy Joel, and other rock-based artists.


Much of the music recorded by singer-songwriters such as Diana Ross, James Taylor, Carly Simon, Carole King and Janis Ian got as much, if not more, airplay on this format than on Top 40 stations. Easy Listening radio also began including songs by artists who had begun in other genres, such as rock and roll or R&B. In addition, several early disco songs, did well on the Adult Contemporary format.


On April 7, 1979, the Easy Listening chart officially became known as Adult Contemporary, and those two words have remained consistent in the name of the chart ever since. Adult contemporary music became one of the most popular radio formats of the 1980s. The growth of AC was a natural result of the generation that first listened to the more "specialized" music of the mid-late 1970s growing older and not being interested in the heavy metal and rap/hip-hop music that a new generation helped to play a significant role in the Top 40 charts by the end of the decade.


Mainstream AC itself has evolved in a similar fashion over the years; traditional AC artists like Barbra Streisand, the Carpenters, Dionne Warwick, Barry Manilow, John Denver, and Olivia Newton-John found it harder to have major Top 40 hits as the 1980s wore on, and due to the influence of MTV, artists who were staples of the Contemporary Hit Radio format, such as Richard Marx, Michael Jackson, Bonnie Tyler, George Michael, Phil Collins, and Laura Branigan began crossing over to the AC charts with greater frequency. Collins has been described by AllMusic as "one of the most successful pop and adult contemporary singers of the '80s and beyond". However, with the combination of MTV and AC radio, adult contemporary appeared harder to define as a genre, with established soft-rock artists of the past still charting pop hits and receiving airplay alongside mainstream radio fare from newer artists at the time.


The amount of crossover between the AC chart and the Hot 100 has varied based on how much the passing pop music trends of the times appealed to adult listeners. Not many disco or new wave songs were particularly successful on the AC chart during the late 1970s and early 1980s, and much of the hip-hop and harder rock music featured on CHR formats later in the decade would have been unacceptable on AC radio.


Although dance-oriented, electronic pop and ballad-oriented rock dominated the 1980s, soft rock songs still enjoyed a mild success thanks to artists like Sheena Easton, Amy Grant, Lionel Richie, Christopher Cross, Dan Hill, Leo Sayer, Billy Ocean, Julio Iglesias, Bertie Higgins and Tommy Page. No song spent more than six weeks at #1 on this chart during the 1980s, with nine songs accomplishing that feat. Two of these were by Lionel Richie, "You Are" in 1983 and "Hello" in 1984, which also reached #1 on the Hot 100.


In 1989, Linda Ronstadt released Cry Like a Rainstorm, Howl Like the Wind, described by critics as "the first true Adult Contemporary album of the decade", featuring American soul singer Aaron Neville on several of the twelve tracks. The album was certified Triple Platinum in the United States alone and became a major success throughout the globe. The Grammy Award-winning singles, "Don't Know Much" and "All My Life", were both long-running #1 Adult Contemporary hits. Several additional singles from the disc made the AC Top 10 as well. The album won over many critics in the need to define AC, and appeared to change the tolerance and acceptance of AC music into mainstream day to day radio play.


The early 1990s marked the softening of urban R&B at the same time alternative rock emerged and traditional pop saw a significant resurgence. This in part led to a widening of the market, not only allowing to cater to more niche markets, but it also became customary for artists to make AC-friendly singles.


Unlike the majority of 1980s mainstream singers, the 1990s mainstream pop/R&B singers such as All-4-One, Boyz II Men, Rob Thomas, Christina Aguilera, Backstreet Boys and Savage Garden generally crossed over to the AC charts. Latin pop artists such as Lynda Thomas, Ricky Martin, Marc Anthony, Selena, Enrique Iglesias and Luis Miguel also enjoyed success in the AC charts.


In addition to Celine Dion, who has had significant success on this chart, other artists with multiple number ones on the AC chart in the 1990s include Mariah Carey, Phil Collins, Michael Bolton, Whitney Houston and Shania Twain. Newer female singer-songwriters such as Sarah McLachlan, Natalie Merchant, Jewel, Melissa Etheridge and Sheryl Crow also broke through on the AC chart during this time.


In 1996, Billboard created a new chart called Adult Top 40, which reflects programming on radio stations that exists somewhere between "adult contemporary" music and "pop" music. Although they are sometimes mistaken for each other, the Adult Contemporary chart and the Adult Top 40 chart are separate charts, and songs reaching one chart might not reach the other. In addition, hot AC is another subgenre of radio programming that is distinct from the Hot Adult Contemporary Tracks chart as it exists today, despite the apparent similarity in name.


In response to the pressure on Hot AC, a new kind of AC format cropped up among American radio recently. The urban adult contemporary format (a term coined by Barry Mayo) usually attracts a large number of African Americans and sometimes Caucasian listeners through playing a great deal of R&B (without any form of rapping), gospel music, classic soul and dance music (including disco).


Another format, rhythmic AC, in addition to playing all the popular hot and soft AC music, past and present, places a heavy emphasis on disco as well as 1980s and 1990s dance hits, such as those by Amber, C&C Music Factory and Black Box, and includes dance remixes of pop songs, such as the Soul Solution mix of Toni Braxton's "Unbreak My Heart".


In its early years of existence, the smooth jazz format was considered to be a form of AC, although it was mainly instrumental, and related a stronger resemblance to the soft AC-styled music. For many years, artists like George Benson, Kenny G and Dave Koz had crossover hits that were played on both smooth jazz and soft AC stations.


A notable pattern that developed during the 2000s and 2010s has been for certain pop songs to have lengthy runs on AC charts, even after the songs have fallen off the Hot 100. Adrian Moreira, senior vice president for adult music for RCA Music Group, said, "We've seen a fairly tidal shift in what AC will play". Rather than emphasizing older songs, adult contemporary was playing many of the same songs as top 40 and adult top 40, but only after the hits had become established. An article on MTV's website by Corey Moss describes this trend: "In other words, AC stations are where pop songs go to die a very long death. Or, to optimists, to get a second life."


With the mixture of radio friendly AC tunes with some rock and pop fare also landing on the pop charts, mainstream songs won over many critics in the need to define AC, and appeared to change the tolerance and acceptance of AC music into mainstream day to day radio play. Part of the reason why more and more hot AC stations are forced to change is that less and less new music fits their bill; most new rock is too alternative for mainstream radio and most new pop is now influenced heavily by dance-pop and electronic dance music.


A popular trend in this era was remixing dance music hits into adult contemporary ballads, especially in the US, (for example, the "Candlelight Mix" versions of "Heaven" by DJ Sammy, "Listen To Your Heart" by D.H.T., and "Everytime We Touch" by Cascada). Adult contemporary has long characterized itself as family-friendly, but edited versions of "Perfect" by P!nk and "Forget You" by Cee Lo Green showed up in the format in 2011.


While most artists became established in other formats before moving to adult contemporary, Michael Bublé and Josh Groban started out as AC artists. Throughout this decade, artists such as Nick Lachey, James Blunt, John Mayer, Bruno Mars, Jason Mraz, Kelly Clarkson, Adele, Clay Aiken and Susan Boyle have become successful thanks to a ballad heavy sound. Much as some hot AC and modern rock artists have crossed over into each other, so too has soft AC crossed with country music in this decade. Country musicians such as Faith Hill, Shania Twain, LeAnn Rimes and Carrie Underwood have had success on both charts.


Since the mid-2000s, the mainstreaming of bands like Wilco and Feist have pushed indie rock into the adult contemporary conversation. In the early 2010s, indie musicians like Imagine Dragons, Mumford & Sons, Of Monsters & Men, The Lumineers and Ed Sheeran also had indie songs that crossed over to the adult contemporary charts.


The consolidation of the "hot AC" format contrasted with the near-demise of most other AC formats: Beginning with the 2005-2007 economic downturn and eventual recession most stations went for the more chart-based CHR, along with the top 40, urban and even Latino formats. Diminishing physical record sales also proved a major blow to the AC genre.


The "soft" AC format has reinvented in the late 2000s/early 2010s as a result of its declining relevance, adopting a more upmarket, middle-of-the-road approach, with a selection of "oldies" (usually from the 1960s/70s onwards), primarily rock, jazz, R&B and pop music. Newer songs are more often (but not limited to) "easy listening" fare, this amount varying depending on the age of the station's target demographic.


Termed "the acoustic equivalent to Prozac", soft adult contemporary, a more adult-oriented version of AC, was born in the late 1970s and grew in the early 1980s. WEEI-FM in Boston was the first station to use the term "soft rock", with ad slogans such as, "Fleetwood Mac ... without the yack" and "Joni ... without the baloney". The vast majority of music played on soft AC stations is mellow, more acoustic, and primarily solo vocalists.


Other popular names for the format include "Warm", "Sunny", "Bee" (or "B") and (particularly in Canada) "EZ Rock". The format can be seen as a more contemporary successor to and combination of the middle of the road (MOR), beautiful music, easy listening and soft rock formats. Many stations in the soft AC format capitalize on its appeal to office workers (many of them females aged 25–54, a key advertiser demographic), and brand themselves as stations "everyone at work can agree on" (KOST originated that phrase as a primary tagline, and other soft AC stations have followed suit).


A large portion of music played on this format are either considered oldies or recurrent. It often deals with modern romantic and sexual relationships (and sometimes other adult themes such as work, raising children, and family) in a thoughtful and complex way. Soft AC, which has never minded keeping songs in high rotation literally for years in some cases, does not appear necessarily to be facing similar pressures to expand its format. Soft AC includes a larger amount of older music, especially classic R&B, soul, and 1960s and 1970s music, than hot AC.


The soft AC format may soon be facing the demographic pressures that the jazz and big band formats faced in the 1960s and 1970s and that the oldies format is starting to face today, with the result that one may hear soft AC less on over-the-air radio and more on satellite radio systems in coming years. Much of the music and artists that were traditionally played on soft AC stations have been relegated to the adult standards format, which is itself disappearing because of aging demographics. Some soft AC stations have found a niche by incorporating more oldies into their playlists and are more open to playing softer songs that fit the "traditional" definition of AC.


Artists contributing to this format include mainly soft rock/pop singers such as, Andy Williams, Johnny Mathis, Nana Mouskouri, Celine Dion, Julio Iglesias, Frank Sinatra, Barry Manilow, Engelbert Humperdinck, and Marc Anthony.


Hot adult contemporary radio stations play a variety of classic hits and contemporary mainstream music aimed at an adult audience. Some Hot AC stations concentrate slightly more on pop music and alternative rock to target the Generation Z audience, though they include the more youth-oriented teen pop, urban and rhythmic dance tracks.


This format often includes dance-pop (such as upbeat songs by Madonna, Cher, Gloria Estefan and Kylie Minogue), power pops (mainly by boybands such as Backstreet Boys and Westlife), and adult-oriented soft rock music that are ballad-driven (typically by Aerosmith[citation needed], The Eagles, Sting, Toto and The Moody Blues). Generally, Hot AC radio stations target their music output towards the 18-54 age group and a demographic audience of both men and women.


Modern adult contemporary can be a variation of hot AC, and includes modern rock titles in its presentation. In 1997, Mike Marino of KMXB in Las Vegas described the format as reaching "an audience that has outgrown the edgier hip-hop or alternative music but hasn't gotten old and sappy enough for the soft ACs." The format's artists included Alanis Morissette, Counting Crows, Gin Blossoms, Bon Jovi, Train, No Doubt, The Script, The Cranberries, Lifehouse, Sarah McLachlan, Sara Bareilles, John Mayer, Jewel, and Ingrid Michaelson. Unlike modern rock, which went after 18-34 men, this format appealed to women.


Urban AC is a form of AC music geared towards adult African-American audiences, and therefore, the artists that are played on these stations are most often black, such as Des'ree, whose album I Ain't Movin' was massively popular amongst both African American audience as well as the wider national audience.


The urban AC stations resemble soft AC rather than hot AC; they play predominantly R&B and soul music with little hip-hop. This is reflected in many of the urban AC radio stations' taglines, such as "Today's R&B and classic soul", "The best variety of R&B hits and oldies" and "(City/Region)'s R&B leader". Urban AC's core artists include Luther Vandross, Trey Songz, Patti LaBelle, Toni Braxton, Whitney Houston, Aretha Franklin, Frank Ocean, Craig David and Mariah Carey.


A more elaborate form of urban AC is the rhythmic oldies format, which focuses primarily on "old school" R&B and soul hits from the 1960s to the 1990s, including Motown and disco hits. The format includes soul or disco artists such as ABBA, The Village People, The Jackson 5, Donna Summer, Tina Charles, Gloria Gaynor and the Bee Gees. Rhythmic oldies stations still exist today, but target African-Americans as opposed to a mass audience.


A format called quiet storm is often included in urban adult contemporary, and is often played during the evening, blending the urban AC and soft AC styles of music. The music that is played is strictly ballads and slow jams, mostly but not limited to Black and Latino artists. Popular artists in the quiet storm format are Teena Marie, Freddie Jackson, Johnny Gill, Lalah Hathaway, Vanessa L. Williams, Toni Braxton, and En Vogue among others.


Anita Baker, Sade, Regina Belle, and Luther Vandross are other examples of artists who appeal to mainstream AC, urban AC and smooth jazz listeners. Some soft AC and urban AC stations like to play smooth jazz on the weekends. In recent years, the Smooth Jazz format has been renamed to Smooth AC, as an attempt to lure younger listeners.


Adult contemporary R&B may be played on both soft AC stations and urban AC. It is a form of neo soul R&B that places emphasis on songcraft and sophistication. As the use of drum machines, synthesizers, and sequencers dominates R&B-rooted music, adult contemporary R&B tends to take most of its cues from the more refined strains of 1970s soul, such as smooth soul, Philly soul and quiet storm. Classic songwriting touches and organic-leaning instrumentation, often featuring string arrangements and horn charts, were constants.


In the 1980s, lush jazz-R&B fusion (George Benson, Patti Austin, Al Jarreau) and stylish crossover R&B (Anita Baker and Luther Vandross, New Edition and Keith Sweat) were equally successful within the mainstream. In the 1990s and early 2000s (decade), artists as sonically contrasting as R. Kelly, Leona Lewis (mainly ballads) and Jill Scott both fit the bill, provided the audience for the material was mature. By riding and contributing to nearly all of the trends, no one has exemplified the style more than Babyface, whose career thrived over 20 years as a member of the Deele (Two Occasions), a solo artist (Whip Appeal, When Can I See You), and a songwriter/producer (Toni Braxton's Breathe Again, Boyz II Men's I'll Make Love to You).


Contemporary Christian music (CCM) has several subgenres, one being "Christian AC". Radio & Records, for instance, lists Christian AC among its format charts. There has been crossover to mainstream and hot AC formats by many of the core artists of the Christian AC genre, notably Amy Grant, Michael W. Smith, Kathy Troccoli, Steven Curtis Chapman, Plumb, and more recently, MercyMe.


In recent years it has become common for many AC stations, particularly soft AC stations, to play primarily or exclusively Christmas music during the Christmas season in November and December. While these tend mostly to be contemporary seasonal recordings by the same few artists featured under the normal format, most stations will also air some vintage holiday tunes from older pop, MOR, and adult standards artists – such as Nat King Cole, Bing Crosby, Dean Martin, The Carpenters, Percy Faith, Johnny Mathis and Andy Williams – many of whom would never be played on these stations during the rest of the year.


These Christmas music marathons typically start during the week before Thanksgiving Day and end after Christmas Day, or sometimes extending to New Year's Day. Afterwards, the stations usually resume their normal music fare. Several stations begin the holiday format much earlier, at the beginning of November. The roots of this tradition can be traced back to the beautiful music and easy listening stations of the 1960s and 1970s.


Daylight saving time (DST) or summer time is the practice of advancing clocks during summer months by one hour so that in the evening daylight is experienced an hour longer, while sacrificing normal sunrise times. Typically, regions with summer time adjust clocks forward one hour close to the start of spring and adjust them backward in the autumn to standard time.


New Zealander George Hudson proposed the modern idea of daylight saving in 1895. Germany and Austria-Hungary organized the first nationwide implementation, starting on 30 April 1916. Many countries have used it at various times since then, particularly since the energy crisis of the 1970s.


The practice has received both advocacy and criticism. Putting clocks forward benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for evening entertainment and for other activities tied to sunlight, such as farming. Although some early proponents of DST aimed to reduce evening use of incandescent lighting, which used to be a primary use of electricity, modern heating and cooling usage patterns differ greatly and research about how DST affects energy use is limited or contradictory.


DST clock shifts sometimes complicate timekeeping and can disrupt travel, billing, record keeping, medical devices, heavy equipment, and sleep patterns. Computer software can often adjust clocks automatically, but policy changes by various jurisdictions of the dates and timings of DST may be confusing.


Industrialized societies generally follow a clock-based schedule for daily activities that do not change throughout the course of the year. The time of day that individuals begin and end work or school, and the coordination of mass transit, for example, usually remain constant year-round. In contrast, an agrarian society's daily routines for work and personal conduct are more likely governed by the length of daylight hours and by solar time, which change seasonally because of the Earth's axial tilt. North and south of the tropics daylight lasts longer in summer and shorter in winter, the effect becoming greater as one moves away from the tropics.


By synchronously resetting all clocks in a region to one hour ahead of Standard Time (one hour "fast"), individuals who follow such a year-round schedule will wake an hour earlier than they would have otherwise; they will begin and complete daily work routines an hour earlier, and they will have available to them an extra hour of daylight after their workday activities. However, they will have one less hour of daylight at the start of each day, making the policy less practical during winter.


While the times of sunrise and sunset change at roughly equal rates as the seasons change, proponents of Daylight Saving Time argue that most people prefer a greater increase in daylight hours after the typical "nine-to-five" workday. Supporters have also argued that DST decreases energy consumption by reducing the need for lighting and heating, but the actual effect on overall energy use is heavily disputed.


The manipulation of time at higher latitudes (for example Iceland, Nunavut or Alaska) has little impact on daily life, because the length of day and night changes more extremely throughout the seasons (in comparison to other latitudes), and thus sunrise and sunset times are significantly out of sync with standard working hours regardless of manipulations of the clock. DST is also of little use for locations near the equator, because these regions see only a small variation in daylight in the course of the year.


Although they did not fix their schedules to the clock in the modern sense, ancient civilizations adjusted daily schedules to the sun more flexibly than modern DST does, often dividing daylight into twelve hours regardless of day length, so that each daylight hour was longer during summer. For example, Roman water clocks had different scales for different months of the year: at Rome's latitude the third hour from sunrise, hora tertia, started by modern standards at 09:02 solar time and lasted 44 minutes at the winter solstice, but at the summer solstice it started at 06:58 and lasted 75 minutes. After ancient times, equal-length civil hours eventually supplanted unequal, so civil time no longer varies by season. Unequal hours are still used in a few traditional settings, such as some Mount Athos monasteries and all Jewish ceremonies.


During his time as an American envoy to France, Benjamin Franklin, publisher of the old English proverb, "Early to bed, and early to rise, makes a man healthy, wealthy and wise", anonymously published a letter suggesting that Parisians economize on candles by rising earlier to use morning sunlight. This 1784 satire proposed taxing shutters, rationing candles, and waking the public by ringing church bells and firing cannons at sunrise. Despite common misconception, Franklin did not actually propose DST; 18th-century Europe did not even keep precise schedules. However, this soon changed as rail and communication networks came to require a standardization of time unknown in Franklin's day.


Modern DST was first proposed by the New Zealand entomologist George Hudson, whose shift-work job gave him leisure time to collect insects, and led him to value after-hours daylight. In 1895 he presented a paper to the Wellington Philosophical Society proposing a two-hour daylight-saving shift, and after considerable interest was expressed in Christchurch, he followed up in an 1898 paper. Many publications credit DST's proposal to the prominent English builder and outdoorsman William Willett, who independently conceived DST in 1905 during a pre-breakfast ride, when he observed with dismay how many Londoners slept through a large part of a summer's day. An avid golfer, he also disliked cutting short his round at dusk. His solution was to advance the clock during the summer months, a proposal he published two years later. The proposal was taken up by the Liberal Member of Parliament (MP) Robert Pearce, who introduced the first Daylight Saving Bill to the House of Commons on 12 February 1908. A select committee was set up to examine the issue, but Pearce's bill did not become law, and several other bills failed in the following years. Willett lobbied for the proposal in the UK until his death in 1915.


Starting on 30 April 1916, Germany and its World War I ally Austria-Hungary were the first to use DST (German: Sommerzeit) as a way to conserve coal during wartime. Britain, most of its allies, and many European neutrals soon followed suit. Russia and a few other countries waited until the next year and the United States adopted it in 1918.


Broadly speaking, Daylight Saving Time was abandoned in the years after the war (with some notable exceptions including Canada, the UK, France, and Ireland for example). However, it was brought back for periods of time in many different places during the following decades, and commonly during the Second World War. It became widely adopted, particularly in North America and Europe starting in the 1970s as a result of the 1970s energy crisis.


Since then, the world has seen many enactments, adjustments, and repeals. For specific details, an overview is available at Daylight saving time by country.


In the case of the United States where a one-hour shift occurs at 02:00 local time, in spring the clock jumps forward from the last moment of 01:59 standard time to 03:00 DST and that day has 23 hours, whereas in autumn the clock jumps backward from the last moment of 01:59 DST to 01:00 standard time, repeating that hour, and that day has 25 hours. A digital display of local time does not read 02:00 exactly at the shift to summer time, but instead jumps from 01:59:59.9 forward to 03:00:00.0.


Clock shifts are usually scheduled near a weekend midnight to lessen disruption to weekday schedules. A one-hour shift is customary, but Australia's Lord Howe Island uses a half-hour shift. Twenty-minute and two-hour shifts have been used in the past.


Coordination strategies differ when adjacent time zones shift clocks. The European Union shifts all at once, at 01:00 UTC or 02:00 CET or 03:00 EET; for example, Eastern European Time is always one hour ahead of Central European Time. Most of North America shifts at 02:00 local time, so its zones do not shift at the same time; for example, Mountain Time is temporarily (for one hour) zero hours ahead of Pacific Time, instead of one hour ahead, in the autumn and two hours, instead of one, ahead of Pacific Time in the spring. In the past, Australian districts went even further and did not always agree on start and end dates; for example, in 2008 most DST-observing areas shifted clocks forward on October 5 but Western Australia shifted on October 26. In some cases only part of a country shifts; for example, in the US, Hawaii and most of Arizona do not observe DST.


Start and end dates vary with location and year. Since 1996 European Summer Time has been observed from the last Sunday in March to the last Sunday in October; previously the rules were not uniform across the European Union. Starting in 2007, most of the United States and Canada observe DST from the second Sunday in March to the first Sunday in November, almost two-thirds of the year. The 2007 US change was part of the Energy Policy Act of 2005; previously, from 1987 through 2006, the start and end dates were the first Sunday in April and the last Sunday in October, and Congress retains the right to go back to the previous dates now that an energy-consumption study has been done. Proponents for permanently retaining November as the month for ending DST point to Halloween as a reason to delay the change in order to allow extra daylight for the evening of October 31.


Beginning and ending dates are roughly the reverse in the southern hemisphere. For example, mainland Chile observed DST from the second Saturday in October to the second Saturday in March, with transitions at 24:00 local time. The time difference between the United Kingdom and mainland Chile could therefore be five hours during the Northern summer, three hours during the Southern summer and four hours a few weeks per year because of mismatch of changing dates.


DST is generally not observed near the equator, where sunrise times do not vary enough to justify it. Some countries observe it only in some regions; for example, southern Brazil observes it while equatorial Brazil does not. Only a minority of the world's population uses DST because Asia and Africa generally do not observe it.


Daylight saving has caused controversy since it began. Winston Churchill argued that it enlarges "the opportunities for the pursuit of health and happiness among the millions of people who live in this country" and pundits have dubbed it "Daylight Slaving Time". Historically, retailing, sports, and tourism interests have favored daylight saving, while agricultural and evening entertainment interests have opposed it, and its initial adoption had been prompted by energy crisis and war.


The fate of Willett's 1907 proposal illustrates several political issues involved. The proposal attracted many supporters, including Balfour, Churchill, Lloyd George, MacDonald, Edward VII (who used half-hour DST at Sandringham), the managing director of Harrods, and the manager of the National Bank. However, the opposition was stronger: it included Prime Minister H. H. Asquith, Christie (the Astronomer Royal), George Darwin, Napier Shaw (director of the Meteorological Office), many agricultural organizations, and theatre owners. After many hearings the proposal was narrowly defeated in a Parliament committee vote in 1909. Willett's allies introduced similar bills every year from 1911 through 1914, to no avail. The US was even more skeptical: Andrew Peters introduced a DST bill to the US House of Representatives in May 1909, but it soon died in committee.


After Germany led the way with starting DST (German: Sommerzeit) during World War I on 30 April 1916 together with its allies to alleviate hardships from wartime coal shortages and air raid blackouts, the political equation changed in other countries; the United Kingdom used DST first on 21 May 1916. US retailing and manufacturing interests led by Pittsburgh industrialist Robert Garland soon began lobbying for DST, but were opposed by railroads. The US's 1917 entry to the war overcame objections, and DST was established in 1918.


The war's end swung the pendulum back. Farmers continued to dislike DST, and many countries repealed it after the war. Britain was an exception: it retained DST nationwide but over the years adjusted transition dates for several reasons, including special rules during the 1920s and 1930s to avoid clock shifts on Easter mornings. The US was more typical: Congress repealed DST after 1919. President Woodrow Wilson, like Willett an avid golfer, vetoed the repeal twice but his second veto was overridden. Only a few US cities retained DST locally thereafter, including New York so that its financial exchanges could maintain an hour of arbitrage trading with London, and Chicago and Cleveland to keep pace with New York. Wilson's successor Warren G. Harding opposed DST as a "deception". Reasoning that people should instead get up and go to work earlier in the summer, he ordered District of Columbia federal employees to start work at 08:00 rather than 09:00 during summer 1922. Some businesses followed suit though many others did not; the experiment was not repeated.


The history of time in the United States includes DST during both world wars, but no standardization of peacetime DST until 1966. In May 1965, for two weeks, St. Paul, Minnesota and Minneapolis, Minnesota were on different times, when the capital city decided to join most of the nation by starting Daylight Saving Time while Minneapolis opted to follow the later date set by state law. In the mid-1980s, Clorox (parent of Kingsford Charcoal) and 7-Eleven provided the primary funding for the Daylight Saving Time Coalition behind the 1987 extension to US DST, and both Idaho senators voted for it based on the premise that during DST fast-food restaurants sell more French fries, which are made from Idaho potatoes.


In 1992, after a three-year trial of daylight saving in Queensland, Australia, a referendum on daylight saving was held and defeated with a 54.5% 'no' vote – with regional and rural areas strongly opposed, while those in the metropolitan south-east were in favor. In 2005, the Sporting Goods Manufacturers Association and the National Association of Convenience Stores successfully lobbied for the 2007 extension to US DST. In December 2008, the Daylight Saving for South East Queensland (DS4SEQ) political party was officially registered in Queensland, advocating the implementation of a dual-time zone arrangement for Daylight Saving in South East Queensland while the rest of the state maintains standard time. DS4SEQ contested the March 2009 Queensland State election with 32 candidates and received one percent of the statewide primary vote, equating to around 2.5% across the 32 electorates contested. After a three-year trial, more than 55% of Western Australians voted against DST in 2009, with rural areas strongly opposed. On 14 April 2010, after being approached by the DS4SEQ political party, Queensland Independent member Peter Wellington, introduced the Daylight Saving for South East Queensland Referendum Bill 2010 into Queensland Parliament, calling for a referendum to be held at the next State election on the introduction of daylight saving into South East Queensland under a dual-time zone arrangement. The Bill was defeated in Queensland Parliament on 15 June 2011.


In the UK the Royal Society for the Prevention of Accidents supports a proposal to observe SDST's additional hour year-round, but is opposed in some industries, such as postal workers and farmers, and particularly by those living in the northern regions of the UK.


In some Muslim countries DST is temporarily abandoned during Ramadan (the month when no food should be eaten between sunrise and sunset), since the DST would delay the evening dinner. Ramadan took place in July and August in 2012. This concerns at least Morocco and Palestine, although Iran keeps DST during Ramadan. Most Muslim countries do not use DST, partially for this reason.


The 2011 declaration by Russia that it would not turn its clocks back and stay in DST all year long was subsequently followed by a similar declaration from Belarus. The plan generated widespread complaints due to the dark of wintertime morning, and thus was abandoned in 2014. The country changed its clocks to Standard Time on 26 October 2014 - and intends to stay there permanently.


Proponents of DST generally argue that it saves energy, promotes outdoor leisure activity in the evening (in summer), and is therefore good for physical and psychological health, reduces traffic accidents, reduces crime, or is good for business. Groups that tend to support DST are urban workers, retail businesses, outdoor sports enthusiasts and businesses, tourism operators, and others who benefit from increased light during the evening in summer.


Opponents argue that actual energy savings are inconclusive, that DST increases health risks such as heart attack, that DST can disrupt morning activities, and that the act of changing clocks twice a year is economically and socially disruptive and cancels out any benefit. Farmers have tended to oppose DST.


Common agreement about the day's layout or schedule confers so many advantages that a standard DST schedule has generally been chosen over ad hoc efforts to get up earlier. The advantages of coordination are so great that many people ignore whether DST is in effect by altering their nominal work schedules to coordinate with television broadcasts or daylight. DST is commonly not observed during most of winter, because its mornings are darker; workers may have no sunlit leisure time, and children may need to leave for school in the dark. Since DST is applied to many varying communities, its effects may be very different depending on their culture, light levels, geography, and climate; that is why it is hard to make generalized conclusions about the absolute effects of the practice. Some areas may adopt DST simply as a matter of coordination with others rather than for any direct benefits.


DST's potential to save energy comes primarily from its effects on residential lighting, which consumes about 3.5% of electricity in the United States and Canada. Delaying the nominal time of sunset and sunrise reduces the use of artificial light in the evening and increases it in the morning. As Franklin's 1784 satire pointed out, lighting costs are reduced if the evening reduction outweighs the morning increase, as in high-latitude summer when most people wake up well after sunrise. An early goal of DST was to reduce evening usage of incandescent lighting, which used to be a primary use of electricity. Although energy conservation remains an important goal, energy usage patterns have greatly changed since then, and recent research is limited and reports contradictory results. Electricity use is greatly affected by geography, climate, and economics, making it hard to generalize from single studies.


Several studies have suggested that DST increases motor fuel consumption. The 2008 DOE report found no significant increase in motor gasoline consumption due to the 2007 United States extension of DST.


Retailers, sporting goods makers, and other businesses benefit from extra afternoon sunlight, as it induces customers to shop and to participate in outdoor afternoon sports. In 1984, Fortune magazine estimated that a seven-week extension of DST would yield an additional $30 million for 7-Eleven stores, and the National Golf Foundation estimated the extension would increase golf industry revenues $200 million to $300 million. A 1999 study estimated that DST increases the revenue of the European Union's leisure sector by about 3%.


Conversely, DST can adversely affect farmers, parents of young children, and others whose hours are set by the sun and they have traditionally opposed the practice, although some farmers are neutral. One reason why farmers oppose DST is that grain is best harvested after dew evaporates, so when field hands arrive and leave earlier in summer their labor is less valuable. Dairy farmers are another group who complain of the change. Their cows are sensitive to the timing of milking, so delivering milk earlier disrupts their systems. Today some farmers' groups are in favor of DST.


Changing clocks and DST rules has a direct economic cost, entailing extra work to support remote meetings, computer applications and the like. For example, a 2007 North American rule change cost an estimated $500 million to $1 billion, and Utah State University economist William F. Shughart II has estimated the lost opportunity cost at around $1.7 billion USD. Although it has been argued that clock shifts correlate with decreased economic efficiency, and that in 2000 the daylight-saving effect implied an estimated one-day loss of $31 billion on US stock exchanges, the estimated numbers depend on the methodology. The results have been disputed, and the original authors have refuted the points raised by disputers.


In 1975 the US DOT conservatively identified a 0.7% reduction in traffic fatalities during DST, and estimated the real reduction at 1.5% to 2%, but the 1976 NBS review of the DOT study found no differences in traffic fatalities. In 1995 the Insurance Institute for Highway Safety estimated a reduction of 1.2%, including a 5% reduction in crashes fatal to pedestrians. Others have found similar reductions. Single/Double Summer Time (SDST), a variant where clocks are one hour ahead of the sun in winter and two in summer, has been projected to reduce traffic fatalities by 3% to 4% in the UK, compared to ordinary DST. However, accidents do increase by as much as 11% during the two weeks that follow the end of British Summer Time. It is not clear whether sleep disruption contributes to fatal accidents immediately after the spring clock shifts. A correlation between clock shifts and traffic accidents has been observed in North America and the UK but not in Finland or Sweden. If this effect exists, it is far smaller than the overall reduction in traffic fatalities. A 2009 US study found that on Mondays after the switch to DST, workers sleep an average of 40 minutes less, and are injured at work more often and more severely.


In the 1970s the US Law Enforcement Assistance Administration (LEAA) found a reduction of 10% to 13% in Washington, D.C.'s violent crime rate during DST. However, the LEAA did not filter out other factors, and it examined only two cities and found crime reductions only in one and only in some crime categories; the DOT decided it was "impossible to conclude with any confidence that comparable benefits would be found nationwide". Outdoor lighting has a marginal and sometimes even contradictory influence on crime and fear of crime.


In several countries, fire safety officials encourage citizens to use the two annual clock shifts as reminders to replace batteries in smoke and carbon monoxide detectors, particularly in autumn, just before the heating and candle season causes an increase in home fires. Similar twice-yearly tasks include reviewing and practicing fire escape and family disaster plans, inspecting vehicle lights, checking storage areas for hazardous materials, reprogramming thermostats, and seasonal vaccinations. Locations without DST can instead use the first days of spring and autumn as reminders.


DST has mixed effects on health. In societies with fixed work schedules it provides more afternoon sunlight for outdoor exercise. It alters sunlight exposure; whether this is beneficial depends on one's location and daily schedule, as sunlight triggers vitamin D synthesis in the skin, but overexposure can lead to skin cancer. DST may help in depression by causing individuals to rise earlier, but some argue the reverse. The Retinitis Pigmentosa Foundation Fighting Blindness, chaired by blind sports magnate Gordon Gund, successfully lobbied in 1985 and 2005 for US DST extensions.


Clock shifts were found to increase the risk of heart attack by 10 percent, and to disrupt sleep and reduce its efficiency. Effects on seasonal adaptation of the circadian rhythm can be severe and last for weeks. A 2008 study found that although male suicide rates rise in the weeks after the spring transition, the relationship weakened greatly after adjusting for season. A 2008 Swedish study found that heart attacks were significantly more common the first three weekdays after the spring transition, and significantly less common the first weekday after the autumn transition. The government of Kazakhstan cited health complications due to clock shifts as a reason for abolishing DST in 2005. In March 2011, Dmitri Medvedev, president of Russia, claimed that "stress of changing clocks" was the motivation for Russia to stay in DST all year long. Officials at the time talked about an annual increase in suicides.


An unexpected adverse effect of daylight saving time may lie in the fact that an extra part of morning rush hour traffic occurs before dawn and traffic emissions then cause higher air pollution than during daylight hours.


DST's clock shifts have the obvious disadvantage of complexity. People must remember to change their clocks; this can be time-consuming, particularly for mechanical clocks that cannot be moved backward safely. People who work across time zone boundaries need to keep track of multiple DST rules, as not all locations observe DST or observe it the same way. The length of the calendar day becomes variable; it is no longer always 24 hours. Disruption to meetings, travel, broadcasts, billing systems, and records management is common, and can be expensive. During an autumn transition from 02:00 to 01:00, a clock reads times from 01:00:00 through 01:59:59 twice, possibly leading to confusion.


Damage to a German steel facility occurred during a DST transition in 1993, when a computer timing system linked to a radio time synchronization signal allowed molten steel to cool for one hour less than the required duration, resulting in spattering of molten steel when it was poured. Medical devices may generate adverse events that could harm patients, without being obvious to clinicians responsible for care. These problems are compounded when the DST rules themselves change; software developers must test and perhaps modify many programs, and users must install updates and restart applications. Consumers must update devices such as programmable thermostats with the correct DST rules, or manually adjust the devices' clocks. A common strategy to resolve these problems in computer systems is to express time using the Coordinated Universal Time (UTC) rather than the local time zone. For example, Unix-based computer systems use the UTC-based Unix time internally.


Some clock-shift problems could be avoided by adjusting clocks continuously or at least more gradually—for example, Willett at first suggested weekly 20-minute transitions—but this would add complexity and has never been implemented.


DST inherits and can magnify the disadvantages of standard time. For example, when reading a sundial, one must compensate for it along with time zone and natural discrepancies. Also, sun-exposure guidelines such as avoiding the sun within two hours of noon become less accurate when DST is in effect.


As explained by Richard Meade in the English Journal of the (American) National Council of Teachers of English, the form daylight savings time (with an "s") was already in 1978 much more common than the older form daylight saving time in American English ("the change has been virtually accomplished"). Nevertheless, even dictionaries such as Merriam-Webster's, American Heritage, and Oxford, which describe actual usage instead of prescribing outdated usage (and therefore also list the newer form), still list the older form first. This is because the older form is still very common in print and preferred by many editors. ("Although daylight saving time is considered correct, daylight savings time (with an "s") is commonly used.") The first two words are sometimes hyphenated (daylight-saving[s] time). Merriam-Webster's also lists the forms daylight saving (without "time"), daylight savings (without "time"), and daylight time.


In Britain, Willett's 1907 proposal used the term daylight saving, but by 1911 the term summer time replaced daylight saving time in draft legislation. Continental Europe uses similar phrases, such as Sommerzeit in Germany, zomertijd in Dutch-speaking regions, kesäaika in Finland, horario de verano or hora de verano in Spain and heure d'été in France, whereas in Italy the term is ora legale, that is, legal time (legally enforced time) as opposed to "ora solare", solar time, in winter.


The name of local time typically changes when DST is observed. American English replaces standard with daylight: for example, Pacific Standard Time (PST) becomes Pacific Daylight Time (PDT). In the United Kingdom, the standard term for UK time when advanced by one hour is British Summer Time (BST), and British English typically inserts summer into other time zone names, e.g. Central European Time (CET) becomes Central European Summer Time (CEST).


The North American mnemonic "spring forward, fall back" (also "spring ahead ...", "spring up ...", and "... fall behind") helps people remember which direction to shift clocks.


Changes to DST rules cause problems in existing computer installations. For example, the 2007 change to DST rules in North America required many computer systems to be upgraded, with the greatest impact on email and calendaring programs; the upgrades consumed a significant effort by corporate information technologists.


Some applications standardize on UTC to avoid problems with clock shifts and time zone differences. Likewise, most modern operating systems internally handle and store all times as UTC and only convert to local time for display.


However, even if UTC is used internally, the systems still require information on time zones to correctly calculate local time where it is needed. Many systems in use today base their date/time calculations from data derived from the IANA time zone database also known as zoneinfo.


The IANA time zone database maps a name to the named location's historical and predicted clock shifts. This database is used by many computer software systems, including most Unix-like operating systems, Java, and the Oracle RDBMS; HP's "tztab" database is similar but incompatible. When temporal authorities change DST rules, zoneinfo updates are installed as part of ordinary system maintenance. In Unix-like systems the TZ environment variable specifies the location name, as in TZ=':America/New_York'. In many of those systems there is also a system-wide setting that is applied if the TZ environment variable isn't set: this setting is controlled by the contents of the /etc/localtime file, which is usually a symbolic link or hard link to one of the zoneinfo files. Internal time is stored in timezone-independent epoch time; the TZ is used by each of potentially many simultaneous users and processes to independently localize time display.


Older or stripped-down systems may support only the TZ values required by POSIX, which specify at most one start and end rule explicitly in the value. For example, TZ='EST5EDT,M3.2.0/02:00,M11.1.0/02:00' specifies time for the eastern United States starting in 2007. Such a TZ value must be changed whenever DST rules change, and the new value applies to all years, mishandling some older timestamps.


As with zoneinfo, a user of Microsoft Windows configures DST by specifying the name of a location, and the operating system then consults a table of rule sets that must be updated when DST rules change. Procedures for specifying the name and updating the table vary with release. Updates are not issued for older versions of Microsoft Windows. Windows Vista supports at most two start and end rules per time zone setting. In a Canadian location observing DST, a single Vista setting supports both 1987–2006 and post-2006 time stamps, but mishandles some older time stamps. Older Microsoft Windows systems usually store only a single start and end rule for each zone, so that the same Canadian setting reliably supports only post-2006 time stamps.


These limitations have caused problems. For example, before 2005, DST in Israel varied each year and was skipped some years. Windows 95 used rules correct for 1995 only, causing problems in later years. In Windows 98, Microsoft marked Israel as not having DST, forcing Israeli users to shift their computer clocks manually twice a year. The 2005 Israeli Daylight Saving Law established predictable rules using the Jewish calendar but Windows zone files could not represent the rules' dates in a year-independent way. Partial workarounds, which mishandled older time stamps, included manually switching zone files every year and a Microsoft tool that switches zones automatically. In 2013, Israel standardized its daylight saving time according to the Gregorian calendar.


Microsoft Windows keeps the system real-time clock in local time. This causes several problems, including compatibility when multi booting with operating systems that set the clock to UTC, and double-adjusting the clock when multi booting different Windows versions, such as with a rescue boot disk. This approach is a problem even in Windows-only systems: there is no support for per-user timezone settings, only a single system-wide setting. In 2008 Microsoft hinted that future versions of Windows will partially support a Windows registry entry RealTimeIsUniversal that had been introduced many years earlier, when Windows NT supported RISC machines with UTC clocks, but had not been maintained. Since then at least two fixes related to this feature have been published by Microsoft.


The NTFS file system used by recent versions of Windows stores the file with a UTC time stamp, but displays it corrected to local—or seasonal—time. However, the FAT filesystem commonly used on removable devices stores only the local time. Consequently, when a file is copied from the hard disk onto separate media, its time will be set to the current local time. If the time adjustment is changed, the timestamps of the original file and the copy will be different. The same effect can be observed when compressing and uncompressing files with some file archivers. It is the NTFS file that changes seen time. This effect should be kept in mind when trying to determine if a file is a duplicate of another, although there are other methods of comparing files for equality (such as using a checksum algorithm).


A move to "permanent daylight saving time" (staying on summer hours all year with no time shifts) is sometimes advocated, and has in fact been implemented in some jurisdictions such as Argentina, Chile, Iceland, Singapore, Uzbekistan and Belarus. Advocates cite the same advantages as normal DST without the problems associated with the twice yearly time shifts. However, many remain unconvinced of the benefits, citing the same problems and the relatively late sunrises, particularly in winter, that year-round DST entails. Russia switched to permanent DST from 2011 to 2014, but the move proved unpopular because of the late sunrises in winter, so the country switched permanently back to "standard" or "winter" time in 2014.


Xinjiang, China; Argentina; Chile; Iceland; Russia and other areas skew time zones westward, in effect observing DST year-round without complications from clock shifts. For example, Saskatoon, Saskatchewan, is at 106°39′ W longitude, slightly west of center of the idealized Mountain Time Zone (105° W), but the time in Saskatchewan is Central Standard Time (90° W) year-round, so Saskatoon is always about 67 minutes ahead of mean solar time, thus effectively observing daylight saving time year-round. Conversely, northeast India and a few other areas skew time zones eastward, in effect observing negative DST. The United Kingdom and Ireland experimented with year-round DST from 1968 to 1971 but abandoned it because of its unpopularity, particularly in northern regions.


Western France, Spain, and other areas skew time zones and shift clocks, in effect observing DST in winter with an extra hour in summer. Nome, Alaska, is at 165°24′ W longitude, which is just west of center of the idealized Samoa Time Zone (165° W), but Nome observes Alaska Time (135° W) with DST, so it is slightly more than two hours ahead of the sun in winter and three in summer. Double daylight saving time has been used on occasion; for example, it was used in some European countries during and shortly after World War II when it was referred to as "Double Summer Time". See British Double Summer Time and Central European Midsummer Time for details.


The Royal Institute of British Architects (RIBA) is a professional body for architects primarily in the United Kingdom, but also internationally, founded for the advancement of architecture under its charter granted in 1837 and Supplemental Charter granted in 1971.


Originally named the Institute of British Architects in London, it was formed in 1834 by several prominent architects, including Philip Hardwick, Thomas Allom, William Donthorne, Thomas Leverton Donaldson, William Adams Nicholson, John Buonarotti Papworth, and Thomas de Grey, 2nd Earl de Grey.


After the grant of the royal charter it had become known as the Royal Institute of British Architects in London, eventually dropping the reference to London in 1892. In 1934, it moved to its current headquarters on Portland Place, with the building being opened by King George V and Queen Mary.


It was granted its Royal Charter in 1837 under King William IV. Supplemental Charters of 1887, 1909 and 1925 were replaced by a single Charter in 1971, and there have been minor amendments since then.


The original Charter of 1837 set out the purpose of the Royal Institute to be: '… the general advancement of Civil Architecture, and for promoting and facilitating the acquirement of the knowledge of the various arts and sciences connected therewith…'


The operational framework is provided by the Byelaws, which are more frequently updated than the Charter. Any revisions to the Charter or Byelaws require the Privy Council's approval.


The design of the Institute's Mycenean lions medal and the motto ‘Usui civium, decori urbium' has been attributed to Thomas Leverton Donaldson, who had been honorary secretary until 1839. The RIBA Guide to its Archive and History (Angela Mace,1986) records that the first official version of this badge was used as a bookplate for the Institute's library and publications from 1835 to 1891, when it was redesigned by J.H.Metcalfe. It was again redesigned in 1931 by Eric Gill and in 1960 by Joan Hassall. The description in the 1837 by-laws was: "gules, two lions rampant guardant or, supporting a column marked with lines chevron, proper, all standing on a base of the same; a garter surrounding the whole with the inscription Institute of British Architects, anno salutis MDCCCXXXIV; above a mural crown proper, and beneath the motto Usui civium decori urbium ".


In the nineteenth and twentieth centuries the RIBA and its members had a leading part in the promotion of architectural education in the United Kingdom, including the establishment of the Architects' Registration Council of the United Kingdom (ARCUK) and the Board of Architectural Education under the Architects (Registration) Acts, 1931 to 1938. A member of the RIBA, Lionel Bailey Budden, then Associate Professor in the Liverpool University School of Architecture, had contributed the article on Architectural Education published in the fourteenth edition of the Encyclopædia Britannica (1929). His School, Liverpool, was one of the twenty schools named for the purpose of constituting the statutory Board of Architectural Education when the 1931 Act was passed.


Soon after the passing of the 1931 Act, in the book published on the occasion of the Institute's centenary celebration in 1934, Harry Barnes, FRIBA, Chairman of the Registration Committee, mentioned that ARCUK could not be a rival of any architectural association, least of all the RIBA, given the way ARCUK was constituted. Barnes commented that the Act's purpose was not protecting the architectural profession, and that the legitimate interests of the profession were best served by the (then) architectural associations in which some 80 per cent of those practising architecture were to be found.


The RIBA Guide to its Archive and History (1986) has a section on the "Statutory registration of architects" with a bibliography extending from a draft bill of 1887 to one of 1969. The Guide's section on "Education" records the setting up in 1904 of the RIBA Board of Architectural Education, and the system by which any school which applied for recognition, whose syllabus was approved by the Board and whose examinations were conducted by an approved external examiner, and whose standard of attainment was guaranteed by periodical inspections by a "Visiting Board" from the BAE, could be placed on the list of "recognized schools" and its successful students could qualify for exemption from RIBA examinations.


The content of the acts, particularly section 1 (1) of the amending act of 1938, shows the importance which was then attached to giving architects the responsibility of superintending or supervising the building works of local authorities (for housing and other projects), rather than persons professionally qualified only as municipal or other engineers. By the 1970s another issue had emerged affecting education for qualification and registration for practice as an architect, due to the obligation imposed on the United Kingdom and other European governments to comply with European Union Directives concerning mutual recognition of professional qualifications in favour of equal standards across borders, in furtherance of the policy for a single market of the European Union. This led to proposals for reconstituting ARCUK. Eventually, in the 1990s, before proceeding, the government issued a consultation paper "Reform of Architects Registration" (1994). The change of name to "Architects Registration Board" was one of the proposals which was later enacted in the Housing Grants, Construction and Regeneration Act 1996 and reenacted as the Architects Act 1997; another was the abolition of the ARCUK Board of Architectural Education.


RIBA Visiting Boards continue to assess courses for exemption from the RIBA's examinations in architecture. Under arrangements made in 2011 the validation criteria are jointly held by the RIBA and the Architects Registration Board, but unlike the ARB, the RIBA also validates courses outside the UK.


The RIBA is a member organisation, with 44,000 members. Chartered Members are entitled to call themselves chartered architects and to append the post-nominals RIBA after their name; Student Members are not permitted to do so. Formerly, fellowships of the institute were granted, although no longer; those who continue to hold this title instead add FRIBA.


RIBA is based at 66 Portland Place, London—a 1930s Grade II* listed building designed by architect George Grey Wornum with sculptures by Edward Bainbridge Copnall and James Woodford. Parts of the London building are open to the public, including the Library. It has a large architectural bookshop, a café, restaurant and lecture theatres. Rooms are hired out for events.


The Institute also maintains a dozen regional offices around the United Kingdom, it opened its first regional office for the East of England at Cambridge in 1966.


RIBA Enterprises is the commercial arm of RIBA, with a registered office in Newcastle upon Tyne, a base at 15 Bonhill Street in London, and an office in Newark. It employs over 250 staff, approximately 180 of whom are based in Newcastle.


Its services include RIBA Insight, RIBA Appointments, and RIBA Publishing. It publishes the RIBA Product Selector and RIBA Journal. In Newcastle is the NBS, the National Building Specification, which has 130 staff and deals with the building regulations and the Construction Information Service. RIBA Bookshops, which operates online and at 66 Portland Place, is also part of RIBA Enterprises.


The British Architectural Library, sometimes referred to as the RIBA Library, was established in 1834 upon the founding of the institute with donations from members. Now, with over four million items, it is one of the three largest architectural libraries in the world and the largest in Europe. Some items from the collections are on permanent display at the Victoria and Albert Museum (V&A) in the V&A + RIBA Architecture Gallery and included in temporary exhibitions at the RIBA and across Europe and North America. Its collections include:


The overcrowded conditions of the library was one of the reasons why the RIBA moved from 9 Conduit Street to larger premises at 66 Portland Place in 1934. The library remained open throughout World War Two and was able to shelter the archives of Modernist architect Adolf Loos during the war.


The library is based at two public sites: the Reading Room at the RIBA's headquarters, 66 Portland Place, London; and the RIBA Architecture Study Rooms in the Henry Cole Wing of the V&A. The Reading Room, designed by the building's architect George Grey Wornum and his wife Miriam, retains its original 1934 Art Deco interior with open bookshelves, original furniture and double-height central space. The study rooms, opened in 2004, were designed by Wright & Wright. The library is funded entirely by the RIBA but it is open to the public without charge. It operates a free education programme aimed at students, education groups and families, and an information service for RIBA members and the public through the RIBA Information Centre.


Since 2004, through the V&A + RIBA Architecture Partnership, the RIBA and V&A have worked together to promote the understanding and enjoyment of architecture.


In 2004, the two institutions created the Architecture Gallery (Room 128) at the V&A showing artefacts from the collections of both institutions, this was the first permanent gallery devoted to architecture in the UK. The adjacent Architecture Exhibition Space (Room 128a) is used for temporary displays related to architecture. Both spaces were designed by Gareth Hoskins Architects. At the same time the RIBA Library Drawing and Archives Collections moved from 21 Portman Place to new facilities in the Henry Cole Wing at the V&A. Under the Partnership new study rooms were opened where members of the public could view items from the RIBA and V&A architectural collections under the supervision of curatorial staff. These and the nearby education room were designed by Wright & Wright Architects.


RIBA runs many awards including the Stirling Prize for the best new building of the year, the Royal Gold Medal (first awarded in 1848), which honours a distinguished body of work, and the Stephen Lawrence Prize for projects with a construction budget of less than £500,000. The RIBA also awards the President's Medals for student work, which are regarded as the most prestigious awards in architectural education, and the RIBA President's Awards for Research. The RIBA European Award was inaugurated in 2005 for work in the European Union, outside the UK. The RIBA National Award and the RIBA International Award were established in 2007. Since 1966, the RIBA also judges regional awards which are presented locally in the UK regions (East, East Midlands, London, North East, North West, Northern Ireland, Scotland, South/South East, South West/Wessex, Wales, West Midlands and Yorkshire).


Architectural design competitions are used by an organisation that plans to build a new building or refurbish an existing building. They can be used for buildings, engineering work, structures, landscape design projects or public realm artworks. A competition typically asks for architects and/or designers to submit a design proposal in response to a given Brief. The winning design will then be selected by an independent jury panel of design professionals and client representatives. The independence of the jury is vital to the fair conduct of a competition.


In addition to the Architects Registration Board, the RIBA provides accreditation to architecture schools in the UK under a course validation procedure. It also provides validation to international courses without input from the ARB.


The RIBA has three parts to the education process: Part I which is generally a three-year first degree, a year-out of at least one year work experience in an architectural practice precedes the Part II which is generally a two-year post graduate diploma or masters. A further year out must be taken before the RIBA Part III professional exams can be taken. Overall it takes a minimum of seven years before an architecture student can seek chartered status.


In 2007, RIBA called for minimum space standards in newly built British houses after research was published suggesting that British houses were falling behind other European countries. "The average new home sold to people today is significantly smaller than that built in the 1920s... We're way behind the rest of Europe—even densely populated Holland has better proportioned houses than are being built in the country. So let's see minimum space standards for all new homes," said RIBA president Jack Pringle.


The National Archives and Records Administration (NARA) is an independent agency of the United States government charged with preserving and documenting government and historical records and with increasing public access to those documents, which comprise the National Archives. NARA is officially responsible for maintaining and publishing the legally authentic and authoritative copies of acts of Congress, presidential proclamations and executive orders, and federal regulations. The NARA also transmits votes of the Electoral College to Congress.


The Archivist of the United States is the chief official overseeing the operation of the National Archives and Records Administration. The Archivist not only maintains the official documentation of the passage of amendments to the U.S. Constitution by state legislatures, but has the authority to declare when the constitutional threshold for passage has been reached, and therefore when an act has become an amendment.


The Office of the Federal Register publishes the Federal Register, Code of Federal Regulations, and United States Statutes at Large, among others. It also administers the Electoral College.


The National Historical Publications and Records Commission (NHPRC)—the agency's grant-making arm—awards funds to state and local governments, public and private archives, colleges and universities, and other nonprofit organizations to preserve and publish historical records. Since 1964, the NHPRC has awarded some 4,500 grants.


The Office of Government Information Services (OGIS) is a Freedom of Information Act (FOIA) resource for the public and the government. Congress has charged NARA with reviewing FOIA policies, procedures and compliance of Federal agencies and to recommend changes to FOIA. NARA's mission also includes resolving FOIA disputes between Federal agencies and requesters.


Originally, each branch and agency of the U.S. government was responsible for maintaining its own documents, which often resulted in records loss and destruction. Congress established the National Archives Establishment in 1934 to centralize federal record keeping, with the Archivist of the United States as chief administrator. The National Archives was incorporated with GSA in 1949; in 1985 it became an independent agency as NARA (National Archives and Records Administration).


The first Archivist, R.D.W. Connor, began serving in 1934, when the National Archives was established by Congress. As a result of a first Hoover Commission recommendation, in 1949 the National Archives was placed within the newly formed General Services Administration (GSA). The Archivist served as a subordinate official to the GSA Administrator until the National Archives and Records Administration became an independent agency on April 1, 1985.


In March 2006, it was revealed by the Archivist of the United States in a public hearing that a memorandum of understanding between NARA and various government agencies existed to "reclassify", i.e., withdraw from public access, certain documents in the name of national security, and to do so in a manner such that researchers would not be likely to discover the process (the U.S. reclassification program). An audit indicated that more than one third withdrawn since 1999 did not contain sensitive information. The program was originally scheduled to end in 2007.


In 2010, Executive Order 13526 created the National Declassification Center to coordinate declassification practices across agencies, provide secure document services to other agencies, and review records in NARA custody for declassification.


NARA's holdings are classed into "record groups" reflecting the governmental department or agency from which they originated. Records include paper documents, microfilm, still pictures, motion pictures, and electronic media.


Archival descriptions of the permanent holdings of the federal government in the custody of NARA are stored in Archival Research Catalog (ARC). The archival descriptions include information on traditional paper holdings, electronic records, and artifacts. As of December 2012, the catalog consisted of about 10 billion logical data records describing 527,000 artifacts and encompassing 81% of NARA's records. There are also 922,000 digital copies of already digitized materials.


Most records at NARA are in the public domain, as works of the federal government are excluded from copyright protection. However, records from other sources may still be protected by copyright or donor agreements. Executive Order 13526 directs originating agencies to declassify documents if possible before shipment to NARA for long-term storage, but NARA also stores some classified documents until they can be declassified. Its Information Security Oversight Office monitors and sets policy for the U.S. government's security classification system.


Many of NARA's most requested records are frequently used for genealogy research. This includes census records from 1790 to 1930, ships' passenger lists, and naturalization records.


The National Archives Building, known informally as Archives I, located north of the National Mall on Constitution Avenue in Washington, D.C., opened as its original headquarters in 1935. It holds the original copies of the three main formative documents of the United States and its government: the Declaration of Independence, the Constitution, and the Bill of Rights. It also hosts a copy of the 1297 Magna Carta confirmed by Edward I. These are displayed to the public in the main chamber of the National Archives, which is called the Rotunda for the Charters of Freedom. The National Archives Building also exhibits other important American historical documents such as the Louisiana Purchase Treaty, the Emancipation Proclamation, and collections of photography and other historically and culturally significant American artifacts.


Once inside the Rotunda for the Charters of Freedom, there are no lines to see the individual documents and visitors are allowed to walk from document to document as they wish. For over 30 years the National Archives have forbidden flash photography but the advent of cameras with automatic flashes have made the rules increasingly difficult to enforce. As a result, all filming, photographing, and videotaping by the public in the exhibition areas has been prohibited since February 25, 2010.


Because of space constraints, NARA opened a second facility, known informally as Archives II, in 1994 near the University of Maryland, College Park campus (8601 Adelphi Road, College Park, MD, 20740-6001). Largely because of this proximity, NARA and the University of Maryland engage in cooperative initiatives. The College Park campus includes an archaeological site that was listed on the National Register of Historic Places in 1996.


The Washington National Records Center (WNRC), located in Suitland, Maryland is a large warehouse type facility which stores federal records which are still under the control of the creating agency. Federal government agencies pay a yearly fee for storage at the facility. In accordance with federal records schedules, documents at WNRC are transferred to the legal custody of the National Archives after a certain point (this usually involves a relocation of the records to College Park). Temporary records at WNRC are either retained for a fee or destroyed after retention times has elapsed. WNRC also offers research services and maintains a small research room.


The National Archives Building in downtown Washington holds record collections such as all existing federal census records, ships' passenger lists, military unit records from the American Revolution to the Philippine–American War, records of the Confederate government, the Freedmen's Bureau records, and pension and land records.


There are facilities across the country with research rooms, archival holdings, and microfilms of documents of federal agencies and courts pertinent to each region.


In addition, Federal Records Centers exist in each region that house materials owned by Federal agencies. Federal Records Centers are not open for public research. For example, the FRC in Lenexa, Kansas holds items from the treatment of John F. Kennedy after his fatal shooting in 1963.


NARA also maintains the Presidential Library system, a nationwide network of libraries for preserving and making available the documents of U.S. presidents since Herbert Hoover. The Presidential Libraries include:


Libraries and museums have been established for other presidents, but they are not part of the NARA presidential library system, and are operated by private foundations, historical societies, or state governments, including the Abraham Lincoln, Rutherford B. Hayes, William McKinley, Woodrow Wilson and Calvin Coolidge libraries. For example, the Abraham Lincoln Presidential Library and Museum is owned and operated by the state of Illinois.


In an effort to make its holdings more widely available and more easily accessible, the National Archives began entering into public–private partnerships in 2006. A joint venture with Google will digitize and offer NARA video online. When announcing the agreement, Archivist Allen Weinstein said that this pilot program is


On January 10, 2007, the National Archives and Fold3.com (formerly Footnote) launched a pilot project to digitize historic documents from the National Archives holdings. Allen Weinstein explained that this partnership would "allow much greater access to approximately 4.5 million pages of important documents that are currently available only in their original format or on microfilm" and "would also enhance NARA's efforts to preserve its original records."


In July 2007, the National Archives announced it would make its collection of Universal Newsreels from 1929 to 1967 available for purchase through CreateSpace, an Amazon.com subsidiary. During the announcement, Weinstein noted that the agreement would "... reap major benefits for the public-at-large and for the National Archives." Adding, "While the public can come to our College Park, MD research room to view films and even copy them at no charge, this new program will make our holdings much more accessible to millions of people who cannot travel to the Washington, DC area." The agreement also calls for CreateSpace partnership to provide the National Archives with digital reference and preservation copies of the films as part of NARA's preservation program.


In May 2008, the National Archives announced a five-year agreement to digitize selected records including the complete U.S. Federal Census Collection, 1790–1930, passenger lists from 1820–1960 and WWI and WWII draft registration cards. The partnership agreement allows for exclusive use of the digitized records by Ancestry.com for a 5-year embargo period at which point the digital records will be turned over to the National Archives.


On June 18, 2009, the National Archives announced the launching of a YouTube channel "to showcase popular archived films, inform the public about upcoming events around the country, and bring National Archives exhibits to the people." Also in 2009, the National Archives launched a Flickr photostream to share portions of its photographic holdings with the general public. A new teaching with documents website premiered in 2010 and was developed by the education team. The website features 3,000 documents, images, and recordings from the holdings of the Archives. The site also features lesson plans and tools for creating new classroom activities and lessons.


In 2011 the National Archives initiated a Wikiproject on the English Wikipedia to expand collaboration in making its holdings widely available through Wikimedia.


Tristan da Cunha /ˈtrɪstən də ˈkuːnjə/, colloquially Tristan, is both a remote group of volcanic islands in the south Atlantic Ocean and the main island of that group. It is the most remote inhabited archipelago in the world, lying 2,000 kilometres (1,200 mi) from the nearest inhabited land, Saint Helena, 2,400 kilometres (1,500 mi) from the nearest continental land, South Africa, and 3,360 kilometres (2,090 mi) from South America. The territory consists of the main island, also named Tristan da Cunha, which has a north–south length of 11.27 kilometres (7.00 mi) and has an area of 98 square kilometres (38 sq mi), along with the smaller, uninhabited Nightingale Islands and the wildlife reserves of Inaccessible and Gough Islands.


Tristan da Cunha is part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha. This includes Saint Helena and equatorial Ascension Island some 3,730 kilometres (2,318 mi) to the north of Tristan. The island has a population of 267 as of January 2016.


The islands were first sighted in 1506 by Portuguese explorer Tristão da Cunha; rough seas prevented a landing. He named the main island after himself, Ilha de Tristão da Cunha, which was anglicised from its earliest mention on British Admiralty charts to Tristan da Cunha Island. Some sources state that the Portuguese made the first landing in 1520, when the Lás Rafael captained by Ruy Vaz Pereira called at Tristan for water. The first undisputed landing was made in 1643 by the crew of the Heemstede, captained by Claes Gerritsz Bierenbroodspot.


The first permanent settler was Jonathan Lambert, from Salem, Massachusetts, United States, who arrived at the islands in December 1810 with two other men. Lambert publicly declared the islands his property and named them the Islands of Refreshment. After being joined by an Andrew Millet, three of the four men died in 1812; however, the survivor among the original three permanent settlers, Thomas Currie (or Tommaso Corri) remained as a farmer on the island.


In 1816, the United Kingdom annexed the islands, ruling them from the Cape Colony in South Africa. This is reported to have primarily been a measure to ensure that the French would be unable to use the islands as a base for a rescue operation to free Napoleon Bonaparte from his prison on Saint Helena. The occupation also prevented the United States from using Tristan da Cunha as a cruiser base, as it had during the War of 1812.


In 1867, Prince Alfred, Duke of Edinburgh and second son of Queen Victoria, visited the islands. The main settlement, Edinburgh of the Seven Seas, was named in honour of his visit. Lewis Carroll's youngest brother, the Reverend Edwin Heron Dodgson, served as an Anglican missionary and schoolteacher in Tristan da Cunha in the 1880s.


The islands were occupied by a garrison of British Marines and a civilian population was gradually built up. Whalers also set up on the islands as a base for operations in the Southern Atlantic. However, the opening of the Suez Canal in 1869, together with the gradual move from sailing ships to coal-fired steam ships, increased the isolation of the islands, as they were no longer needed as a stopping port or for shelter for journeys from Europe to East Asia.


On 12 January 1938 by Letters Patent the islands were declared a dependency of Saint Helena. Prior to roughly this period, passing ships stopped irregularly at the island for a period of mere hours.


During World War II, the islands were used as a top secret Royal Navy weather and radio station codenamed HMS Atlantic Isle, to monitor Nazi U-boats (which were required to maintain radio contact) and shipping movements in the South Atlantic Ocean. The first Administrator, Surgeon Lieutenant Commander E.J.S. Woolley, was appointed by the British government during this time.


In 1958 as part of an experiment, Operation Argus, the United States Navy detonated an atomic bomb 160 kilometres (100 mi) high in the upper atmosphere about 175 kilometres (109 mi) southeast of the main island.


The 1961 eruption of Queen Mary's Peak forced the evacuation of the entire population via Cape Town to England. The following year a Royal Society expedition went to the islands to assess the damage, and reported that the settlement of Edinburgh of the Seven Seas had been only marginally affected. Most families returned in 1963.


On 23 May 2001, the islands experienced an extratropical cyclone that generated winds up to 190 kilometres per hour (120 mph). A number of structures were severely damaged and a large number of cattle were killed, prompting emergency aid, provided by the British government.


On 4 December 2007 an outbreak of an acute virus-induced flu was reported. This outbreak was compounded by Tristan's lack of suitable and sufficient medical supplies.


On 13 February 2008, fire destroyed the fishing factory and the four generators that supplied power to the island. On 14 March 2008, new generators were installed and uninterrupted power was restored. This fire was devastating to the island because fishing is a mainstay of the economy. While a new factory was being planned and built, M/V Kelso came to the island and acted as a factory ship, with island fishermen based on board for stints normally of one week. The new facility was ready in July 2009, for the start of the 2009–10 fishing season.


On 16 March 2011, the freighter MS Oliva ran aground on Nightingale Island, spilling tons of heavy fuel oil into the ocean, leaving an oil slick threatening the island's population of rockhopper penguins. Nightingale Island has no fresh water, so the penguins were transported to Tristan da Cunha for cleaning.


On November 2011, the sailing boat Puma's Mar Mostro participant in Volvo Ocean Race arrived to the island after her mast broke in the first leg from Alicante and Cape Town. This event made the island, its inhabitants and lifestyle known worldwide thanks to the media reports.


The University of Kansas (KU) is a public research university and the largest in the U.S. state of Kansas. KU branch campuses are located in the towns of Lawrence, Wichita, Overland Park, Salina, and Kansas City, Kansas, with the main campus located in Lawrence on Mount Oread, the highest location in Lawrence. Founded March 21, 1865, the university was opened in 1866, under a charter granted by the Kansas State Legislature in 1864 following enabling legislation passed in 1863 under the Kansas State Constitution, adopted two years after the 1861 admission of the former Kansas Territory as the 34th state into the Union following a very famous bloody internal civil war known as "Bleeding Kansas" during the 1850s.


The university's Medical Center and University Hospital are located in Kansas City, Kansas. The Edwards Campus is in Overland Park, Kansas, in the Kansas City metropolitan area. There are also educational and research sites in Parsons and Topeka, and branches of the University of Kansas School of Medicine in Wichita and Salina. The university is one of the 62 members of the Association of American Universities.