Month their calendar. The moon first appears in March, they name this month "Kahlek". This system has been used for hundreds of years and throughout many generations. This calendar is cyclical and relies on the position and shape of the moon. The Gregorian calendar, like the Julian calendar before it, has twelve months: The mean month length of the Gregorian calendar is 30.436875 days. Months existing in the Roman calendar in the past include: The famous mnemonic "Thirty days hath September" is a common way of teaching the lengths of the months in the English-speaking world. Also, note that any five
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.