Gregorian calendar It also specifies its epact relative to 1 January, in contrast with the Julian calendar, which specified it relative to 22 March. The old date was derived from the Greek system: the earlier "Supputatio Romana" specified it relative to 1 January. During the period between 1582, when the first countries adopted the Gregorian calendar, and 1923, when the last European country adopted it, it was often necessary to indicate the date of some event in both the Julian calendar and in the Gregorian calendar, for example, "10/21 February 1750/51", where the dual year accounts for some countries already beginning their
Arabic names of calendar months Arabic names of calendar months The Arabic names of calendar months of the Gregorian calendar are usually phonetic Arabic pronunciations of the corresponding month names used in European languages. An exception is the Assyrian calendar used in Iraq and the Levant, which is inherited from Classical Arabic that correspond to roughly the same time of year. The Gregorian calendar is and has been used in nearly all the countries of the Arab world, in many places long before European occupation of some of them . All Arab states use the Gregorian calendar for civil purposes. The names of the Gregorian