how many time zones across the united states
Time in the United States Time in the United States, by law, is divided into nine standard time zones covering the states and its possessions, with most of the United States observing daylight saving time (DST) for approximately the spring, summer, and fall months. The time zone boundaries and DST observance are regulated by the Department of Transportation. Official and highly precise timekeeping services (clocks) are provided by two federal agencies: the National Institute of Standards and Technology (NIST) (an agency of the Department of Commerce); and its military counterpart, the United States Naval Observatory (USNO). The clocks run by these services are kept synchronized with each other as well as with those of other international timekeeping organizations.
Paris Peace Accords
Western Hemisphere Below is a list of the countries which are in both the Western and Eastern Hemispheres along the 180th meridian, in order from north to south:
Daylight saving time The dates on which clocks are to be shifted also vary with location and year, consequently, the time differences between regions also vary throughout the year. For example, Central European Time is usually six hours behind North American Eastern Time, except for a few weeks in March and October/November, while the United Kingdom and mainland Chile could be five hours apart during the northern summer, three hours during the southern summer, and four hours a few weeks per 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.[41] 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.[42] Moreover, the beginning and ending dates are roughly reversed between the northern and southern hemispheres because spring and autumn are displaced six months. For example, mainland Chile observes DST from the second Saturday in October to the second Saturday in March, with transitions at 24:00 local time.[43] In some countries time is governed by regional jurisdictions within the country so that some jurisdictions shift and others do not; this is currently the case in Australia, Brazil, Canada, Mexico, and the United States.[44][45]
Geographical zone On the basis of latitudinal extent, the globe is divided into three broad heat zones.
Washington, D.C. Washington, D.C., formally the District of Columbia and commonly referred to as "Washington", "the District", or simply "D.C.", is the capital of the United States.