From The Christian Post
While most people know that Easter is the celebration of the resurrection of Jesus, the foundation of the Christian faith, few are aware of how its date is determined.
In the last 20 years, Easter has fallen in the month of March only five times. The last time Easter was on March 27 – like this year – was in 2005. In 2008, it was even earlier, on March 23.
According to the Bible, Jesus was crucified around the time of the Jewish Passover, which celebrates the Israelite exodus from Egypt and falls on the first full moon following the vernal equinox, or the spring day when night and day are exactly the same length. And since the Hebrew calendar is based on both solar and lunar cycles, the date of Passover changes each year.
Lutz Doering, a reader in New Testament and an expert in calendars and festivals from the University of Durham in the United Kingdom, tells BBC, "According to the New Testament, Jesus rose from the dead on a Sunday. However, it is unclear on what day or date the earliest Christians celebrated Easter."
Then how is its date decided? Numerous methods were adopted by various groups and denominations to determine the date.
But the First Council of Nicaea, a gathering of bishops that met in 325 A.D., stipulated that Easter should always be celebrated on the first Sunday after the Paschal full moon, or the first full moon of the spring equinox, which was later fixed at March 21.
Read more at: Christian Post