Changes

Unlike [[Christmas]], which falls on a specific calendar date (December 25 in the Roman Catholic and Protestant traditions; January 8 in the Orthodox ones), Easter is considered a "moveable feast" in Christian liturgy, as its date depends on astronomical events.

Unlike [[Christmas]], which falls on a specific calendar date (December 25 in the Roman Catholic and Protestant traditions; January 8 in the Orthodox ones), Easter is considered a "moveable feast" in Christian liturgy, as its date depends on astronomical events.

The First [[Council of Nicaea]] in 325 AD set only two rules for its calculation: 1) that the date would be independent of the Hebrew calendar used by the Jews and 2) that it be held on a uniform date throughout all Christian churches.  However, the Council did not specify '''''how''''' the date was to be calculated (or, interestingly, that it had to fall on Sunday, but by then that was the standard practice in most churches); the computational process took centuries and has resulted in the second rule not being followed, with the Eastern Orthodox (and some other Orthodox bodies) celebrating it (in most years) on a different date than Roman Catholic/Protestant bodies (usually later).

The First [[Council of Nicaea]] in 325 AD set only two rules for its calculation: 1) that the date would be independent of the Hebrew calendar used by the Jews and 2) that it be held on a uniform date throughout all Christian churches.

[[Bede the Venerable]] would, 400 years later, set forth the general rule for calculating Easter: "The Sunday following the full Moon which falls on or after the equinox will give the lawful Easter."<ref>There are two equinoxes on Earth annually, one in March and one in September; Bede referred to the one in March.  The March Equinox is known as the Spring (or Vernal) Equinox in the Northern Hemisphere, and the Autumnal Equinox in the Southern Hemisphere.  (An equinox is the instant in time when the plane of the Earth's Equator passes through the geometric center of the Sun's disk, and only occurs in March and September.)</ref> The general rule was later modified for two specific components needed to calculate the date: 1) the date of the first full moon is not the actual date on which the moon is full, but is instead the 14th day of the lunar month (this is called the "Paschal full moon", taken from Pascha), and 2) although the astronomical March equinox can take place on March 19, 20, or 21, the equinox date was later fixed as March 21.

*[[Bede the Venerable]] would, 400 years after Nicaea, set forth the general rule of the ''comptus'' for calculating Easter: "The Sunday following the full Moon which falls on or after the equinox will give the lawful Easter."<ref>There are two equinoxes on Earth annually, one in March and one in September; Bede referred to the one in March.  The March Equinox is known as the Spring (or Vernal) Equinox in the Northern Hemisphere, and the Autumnal Equinox in the Southern Hemisphere.  (An equinox is the instant in time when the plane of the Earth's Equator passes through the geometric center of the Sun's disk, and only occurs in March and September.)</ref>

*Bede's rule would be modified to specifically define two components needed to calculate the date: 1) the term "full moon" would be defined, not as the actual date on which the moon is full, but instead as the 14th day of the lunar month (formally called the "Paschal full moon", taken from Pascha), and 2) the Spring Equinox would be fixed as March 21 (the astronomical March equinox can take place on March 19, 20, or 21).

*The Metonic Cycle, a period of approximately 19 years when the phases of the Moon recur at the same time, would then be used to determine when the Paschal full moon event took place, and from that date the date for Easter would be derived.

The date on which the first full moon was to be determined by using the Metonic Cycle, a period of approximately 19 years when the phases of the Moon recur at the same time.

However, Eastern Orthodox churches use the Julian calendar to determine the date of the Paschal full moon, while Western churches use the Gregorian calendar.  This results (most years) in differing Easter dates for the two Christian branches.<ref>This is because the Julian calendar adds a leap day every four years, while the Gregorian calendar modifies that to skip the leap day in years evenly divisible by 100 (e.g. 1900), except that if the year is evenly divisible by 400 (e.g. 2000) the leap day is retained.</ref>  Due to the complexity of the calculations, many websites exist which perform the calculation for both Orthodox and Western churches.

'''{{before on after|2022|04|17|The next Resurrection Sunday will be on April 17, 2022.|Resurrection Sunday is today, April 17, 2022.|{{before on after|2023|04|09|The next Resurrection Sunday will be on April 9, 2023.|Resurrection Sunday is today, April 9, 2023.|{{before on after|2024|03|31|The next Resurrection Sunday will be on March 31, 2024.|Resurrection Sunday is today, March 31, 2024.| }}}}}}'''

 

'''{{before on after|2021|04|04|The next Resurrection Sunday will be on April 4, 2021.|Resurrection Sunday is today, April 4, 2021.|{{before on after|2022|04|17|The next Resurrection Sunday will be on April 17, 2022.|Resurrection Sunday is today, April 17, 2022.|{{before on after|2023|04|09|The next Resurrection Sunday will be on April 9, 2023.|Resurrection Sunday is today, April 9, 2023.|{{before on after|2024|03|31|The next Resurrection Sunday will be on March 31, 2024.|Resurrection Sunday is today, March 31, 2024.| }}}}}}}}'''

== Lent ==

== Lent ==