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
Tammuz (Babylonian calendar) Tammuz (Babylonian calendar) Tammuz was a month in the Babylonian calendar, named for one of the main Babylonian gods, Tammuz (Sumerian: "Dumuzid", "son of life"). Many different calendar systems have since adopted Tammuz to refer to a month in the summer season. In the Hebrew calendar, Tammuz is the tenth month of the civil year and the fourth month of the ecclesiastical year on the Hebrew calendar. It is a summer month of 29 days. Tammuz is also the name for the month of July in the Gregorian calendar in Arabic (تموز), Syriac ("ܬܡܘܙ") and Turkish ("Temmuz"). The festival for