Adoption of the Gregorian calendar for secular use occurred in Eastern Orthodox countries as late as the 20th century and some religious groups in some of these countries still use the "old style" (O.S.) Julian calendar for ecclesiastical purposes. The Kingdom of Bulgaria changed from the Julian to the Gregorian calendar during the First World War on 31 March 1916, where the next day was 14 April 1916. The Ottoman Empire's Rumi calendar, used for fiscal purposes, was realigned from a Julian to a Gregorian starting on 16 February/ 1 March 1917. The beginning of the year was reset to 1 January starting in 1918.
Kartik (month) name of the month is derived from the name of the star Krittika (কৃত্তিকা). It marks the start of the dry season ( "Hemôntô"). "Kārttikai" (கார்த்திகை, ) is the eighth month of the Tamil calendar used by Tamils across the world. It corresponds to November/December in the Gregorian calendar. It begins when the sun enters the sign of Scorpio. Many festivals, such as Karthikai Deepam, are celebrated in this month. The name of the month is derived from a star, "kārttikai" (கார்த்திகை). According to the Bikram Sambat calendar of Nepal, which is also the country's official calendar, Kartik is the