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 calendar consists of both a lunar calendar and a solar calendar. The Khmer solar calendar is used more commonly than the lunar calendar. There are 12 months and the numbers of days follow the Julian and Gregorian calendar. The Khmer lunar calendar contains 12 months; however, the eighth month is repeated (as a "leap-month") every two or three years, making 13 months instead of 12. The Tongan calendar is based on the cycles of the moon around the earth in one year. The months are: The Sinhala calendar is the Buddhist calendar in Sri Lanka with Sinhala names. Each full