Easter Calendar Date in 2009: April 12
One of the holiest festivals of the Christians, Easter commemorates the Resurrection of Jesus after his Crucifixion. Like the origin of the festival, the precise date of Easter Sunday too has been a matter of contention. Easter and the holidays that are related to it are moveable feasts, in that they do not fall on a fixed date in the Gregorian or Julian calendars (which follow the motion of the sun and the seasons). Instead, they are based on a lunar calendar.
Early Christians celebrated Easter on different days of the week. In 325 AD, the Council of Nicaea convoked by Emperor Constantine issued the Easter Rule which states that Easter shall be celebrated on the first Sunday that occurs after the first full moon on or after the vernal equinox.
However, the "full moon" in the rule is the ecclesiastical full moon and it does not always occur on the same date as the astronomical full moon. The ecclesiastical "vernal equinox" is always on March 21. Therefore, Easter must be celebrated on a Sunday between the dates of March 22 and April 25.
