Rina Mohammed
The official Christian church calendar is a table containing the holy days, saints' days, and festivals of the church, with the dates of the civil calendar on which they occur. After the Reformation, the German Lutheran church retained the Roman calendar, as did the Church of England and some Anglican churches.
The Jewish calendar, derived from the ancient Hebrew calendar, has remained unchanged since about AD 900. It is the official calendar of the modern state of Israel and is used by Jewish people throughout the world as a religious calendar. The starting point of it is the year 3761 BC, the date for the creation of the world aas described in the Old Testament. The calendar is lunisolar, based on lunar months of 29 days alternating with 30 days. An extra month is added every three years, based in the cycle of 19 years. Dates of the Jewish calendar are designated AM (Latin anno mundi, "the year of the world") and BCE (before common era).
Another major religious calendar is the Islamic calendar, a lunar one used in most Muslim countries. It started from AD 622, the day after Hegira, or flight of Mohammed from Mecca to Medina. The Islamic year consists of 12 months. The Islamic date corresponding to a date in Gregorian calendar can be computed by a rule with a maximum error of one day.