Adoption of the Gregorian calendar Julian to the Gregorian calendar. For example, in the article "The October (November) Revolution" the "Encyclopædia Britannica" uses the format of "25 October (7 November, New Style)" to describe the date of the start of the revolution. Other countries of eastern Europe, most notably Eastern Orthodox countries, adopted the Gregorian calendar in the 1910s or early 1920s. The last country of Eastern Orthodox Europe to adopt the Gregorian calendar for civil purposes was Greece, at the time under military administration following the 11 September 1922 Revolution, with Wednesday 15 February 1923 being followed by Thursday 1 March 1923. The Soviet
Month quarter of a day shorter than the solar year and stellar events "wandered" through the calendar, it is referred to as Annus Vagus or "Wandering Year". The Nisga'a calendar coincides with the Gregorian calendar with each month referring to the type of harvesting that is done during the month. This calendar was proposed during the French Revolution, and used by the French government for about twelve years from late 1793. There were twelve months of 30 days each, grouped into three ten-day weeks called "décades". The five or six extra days needed to approximate the tropical year were placed after