St. Thomas

Question: Father, You told us why Easter varies between Greek and Roman Churches, but what does that have to do with the moon?
Answer:   Ah, that can be confusing. We follow a solar calendar that has the same number of days each year. The Jewish calendar is a lunar calendar, based on the cycles of the moon. Their holidays and years are marked by the phases of the moon. There are 354.37 days in a lunar year, which does not evenly line up with a solar year. Since Passover is calculated by the moon, and Jesus died and rose during that holiday, we try to line up our calendar to the lunar cycle like Passover is. Once, people wanted to make Easter the same as Passover (the 14th day of Nisan), but the Church rejected that idea. It was determined that Easter must be on a Sunday, as this was the day of the week on which Christ rose from the tomb, and so is sacred to all Christians as the Lord’s Day. Easter is roughly calculated as the first Sunday after the first full moon after the Vernal Equinox. Since the lunar and solar calendars vary by 10.8725 days, there are extra months added in every few lunar years to accommodate for seasonal shift. That is why Easter may vary in times between March and April, since we are trying to line up phases of the moon to a set date on a solar calendar. It all has to do with the beginning of spring and the date of the full moon.