Date: Weekday: The Islamic calendar is purely lunar and consists of twelve alternating months of 30 and 29 days, with the final 29 day month extended to 30 days during leap years. Began on September 11, 2004, and will end cugrent September 10, 2005, in the. But for the period between the first introduction of the Gregorian calendar on 15 October 1582 and its introduction in Britain on 14 September 1752, there can be considerable confusion between events in continental western Europe and in British domains in English language histories. The Ethiopian Calendar Amharic: የኢትዮጵያ ዘመን አቆጣጠር is the principal calendar used by Ethiopian Amharic Language users and also serves as the liturgical calendar for Ethiopia and Eritrea. The reform was cureent modification of a proposal made bywho proposed to reduce the number of that occur in every four centuries from 100 to 97, by making 3 out of 4 centurial years common years instead of leap years. The Gregorian calendar was used in Bosnia and Herzegovi