This article or section should be merged with Liturgical year

The Christian Calendar organizes days of the year on which Christian festivals occur.

Some Christian festivals and when they occur according to Roman and Protestant (Western) Christianity are:

• Epiphany: 6 January
• Shrove Tuesday: The day before Ash Wednesday
• Ash Wednesday: 44 days before Good Friday
• Palm Sunday: The Sunday before Easter
• Maundy Thursday: The Thursday before Easter
• Good Friday: The Friday before Easter
• Easter: calculated by Computus - Easter Sunday is the first Sunday after the 14th day of the lunar month that falls on or after 21 March.
• Whitsun or Pentecost: Seven weeks after Easter
• Whitmonday: The day after Whitsun or Pentecost
• Christmas: 25 December

In a few, predominantly Eastern Orthodox, nations, religious holidays are celebrated on the corresponding day in the Julian Calendar. From 1900 until 2100, there is a thirteen-day difference between the Julian and the Gregorian Calendar, which is used in most of the world as well as in Eastern Orthodox countries for civil purposes. Thus, for example, Christmas is celebrated on January 6 in these countries. The computation of the day of Easter is, however, completely different between the two calendars and does not differ in any straightforward way.

See also Liturgical year and Calendar of saints, and compare Julian calendar and Gregorian calendar. Christian calendars need to be concerned with computing the date of Easter.