Eastern celebrations: Orthodox and Western churches have different dates.

Orthodox Christians celebrate Easter on April 12th. This is later than the Easter celebrations of Western churches. The article explains why the dates are different.

The difference in dates is due to the calendars used by the churches. Orthodox Christians use the Julian calendar. Western churches use the Gregorian calendar. This calendar difference means Easter falls on different days for each group. The article looks at the history of these calendar differences and how they affect Easter celebrations.

Summarized from the sources above. Read the originals for the full story.