When is Easter in 2014? Depends on the Church
When is Easter in 2014? That depends on if you are a Western Christian or an Eastern Christian. Fortunately this year Easter for both are on the same date in 2014, April 20th. But next year in 2015 Easter will fall on separate dates for the two groups. West and East won't celebrate Easter on the same day again until 2017 when Easter Sunday will fall on April 16th according to www.about.com.
Western Christianity can include Roman Catholics, Protestants, Mormons, and other non-denominational churches. Eastern Christianity includes those of Russian and Greek Orthodox Churches as well as a number of others.
The reason is the two groups use different calendars. The Orthodox Churches use the much older Julian calendar while the Western Churches use the updated Gregorian calendar, which is the one in popular use in the USA and other Western countries. The calendar hanging on your fridge is probably the Gregorian calendar. The Julian calendar dates back to 45 BC and was introduced by Julius Cesar. The Gregorian calendar dates back to 1582 AD when Pope Gregory XIII introduced it according to www.timeanddate.com. The Julian calendar had a discrepancy that added days every so often.
On a side note, both Christian groups also celebrate Christmas on different dates because of their calendars.