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.
Dhanu (month) Dhanu (month) Dhanu, or Dhanus, is a month in the Hindu calendar, Malayalam calendar and others. It corresponds to the zodiacal sign of Sagittarius, and overlaps with approximately the second half of December and about the first half of January in the Gregorian calendar. In Vedic texts, the Dhanus month is called Sahas (IAST: Sahas), but in these ancient texts it has no zodiacal associations. The solar month of Dhanu overlaps with its lunar month Pausha, in Hindu lunisolar calendars. The Dhanu marks the winter season for the Indian subcontinent. It is preceded by the solar month of Vṛścik‌‌‌a, and