Proleptic Gregorian calendar Proleptic Gregorian calendar The proleptic Gregorian calendar is produced by extending the Gregorian calendar backward to dates preceding its official introduction in 1582. In countries that adopted the Gregorian calendar later, dates occurring in the interim (between 1582 and the local adoption) are sometimes "Gregorianized" as well. For example, George Washington was born on February 11, 1731 (Old Style), as Great Britain and its possessions were using the Julian calendar with English years starting on March 25 until September 1752. After the switch, that day became February 22, 1732, which is the date commonly given as Washington's birthday. The proleptic
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