(NEXSTAR) — Did you find yourself having to check the calendar a few times to find out what date Sunday Easter landed on? In case you haven’t noticed, it’s earlier this year than last, when it fell on April 9. This isn’t the earliest we’ve ever celebrated Easter, but it is much earlier than we will in 2025.
So why is Easter never on the same Sunday two years in a row?
Easter, the Christian festivity that marks the resurrection of Jesus, will always fall in March or April. To understand why it always moves around, you have to look at the moon.
“The date of Easter is determined by the moon. Easter always falls on the first Sunday after the first full moon after the vernal equinox,” Kim Mandelkow, director of the Office for Worship with the Archdiocese of Milwaukee, previously told Nexstar.
This year, the first full moon after the first day of spring (which was March 19) was on Monday, March 25, putting Easter on Sunday, March 31. If we hadn’t had a Leap Day this year, Easter would have fallen on March 30.
“The moon is not regular,” Father Martin Schlag, a professor and chair of Catholic social thought at the University of St. Thomas in Minnesota, explained. “It doesn’t follow the solar calendar, but it has its own lunar calendar that varies every year.”
Should the first full moon after spring begins land on a Sunday, Easter would be pushed back a week, according to Mandelkow.
The earliest we’ll ever celebrate Easter is March 22, while the latest is April 25.
Having Easter on either of those days, though, is relatively rare, according to data from the U.S. Census Bureau. You’re actually most likely to see Easter falling on March 31 or April 16, which have the greatest frequencies of claiming the holiday.
We also saw a unique but not uncommon occurrence this year: Ash Wednesday (the first day of Lent) landed on Valentine’s Day. In 2029, the dates will fall on the same Wednesday again (and Easter will fall on April Fools’ Day), but that will be the last time the holidays will share a date for the rest of the century.
And in case you’re already curious, Easter falls on April 20 in 2025.