Easter 3 - Why is the date of Easter so confusing?

Why is the date of Easter different every year and how do they determine it?

Have you ever wondered why Easter Sunday can fall anywhere between March 22 and April 25? This is a good question with answers that require a bit of explanation.

Since the days of early church history, determining the precise date of Easter has been a matter for continued argument. For one, the followers of Christ neglected to record the exact date of Jesus' resurrection. From then on the matter grew increasingly complex.

The four Gospels make it clear that Jesus was crucified in conjunction with the Jewish Passover (Matthew 26:17-19; Mark 14:12-16; Luke 22:7-15; John 18:28,39; 19:14). The four Gospels also make it clear that Jesus was raised from the dead three days later, on the first day of the week (Matthew 28:1; Mark 16:2,9; Luke 24:1; John 20:1,19). Biblically speaking, then, Christ’s resurrection should be celebrated on the first Sunday after the Jewish Passover meal. However, this is not the case.


At the heart of the matter lies a very simple explanation: The early church fathers wished to keep the observance of Easter in correlation to the Jewish Passover. Because the death, burial, and resurrection of Jesus Christ happened after the Passover, they wanted Easter to always be celebrated subsequent to the Passover. And, since the Jewish holiday calendar is based on solar and lunar cycles, each feast day is movable, with dates shifting from year to year. Easter marks the Resurrection of Jesus three days after his Crucifixion.

Easter is observed on the Sunday after the first full moon on or after the day of the vernal equinox (where the sun is directly over the equator in the spring of the Northern Hemisphere). Since our calendar is based on the movement of the Earth and not the movement of the Moon, Easter falls on different dates every year.

The calculation of Easter is complicated because it is linked to (an inaccurate version of) the Hebrew calendar. Jesus was crucified immediately after the Jewish Passover (Luke 22:15), which is a celebration of the Exodus from Egypt under Moses. Celebration of Passover started on the 14th or 15th day of the (spring) month of Nisan. Jewish months start when the moon is new, therefore the 14th or 15th day of the month must be immediately after a full moon.

The formulas can be taken as a good indication of when Easter was celebrated in the Western Church from approximately the 6th century. Today in Western Christianity, Easter is always celebrated on the Sunday immediately following the Paschal Full Moon date of the year. (In actuality, the date of the Paschal Full Moon is determined from historical tables, and has no correspondence to lunar events.)

As astronomers were able to approximate the dates of all the full moons in future years, the Western Christian Church used these calculations to establish a table of Ecclesiastical Full Moon dates. These dates would determine the Holy Days on the Ecclesiastical calendar. In Western Christianity, Easter is always celebrated on the Sunday immediately following the Paschal Full Moon. The Paschal Full Moon can vary as much as two days from the date of the actual full moon, with dates ranging from March 21 to April 18. As a result, Easter dates can range from March 22 through April 25 in Western Christianity.

For this means of measurement it can be understood why the dates of future Easters will appear to be in such flux:

· 2011: April 24

· 2012: April 8

· 2013: March 31

· 2014: April 20

Why Easter Will Never be in May?

For those wondering why the holiday doesn't just go flying all over the calendar, the answer lies in its anchor: the moon cycle. The moon cycle is just under 30 days, meaning that the Easter holiday can never stray more than 36 days beyond the vernal equinox since it occurs on the first Sunday after the full moon.