BILLINGS — However it is celebrated, Easter is a difficult day to track.
For both Western and Orthodox churches, Easter’s date changes from year to year. For Western churches, it can fall anywhere from March 22 to April 25, while the Orthodox Easter dates range from April 4 to May 8.
How the date is determined goes back to Christianity's roots, said the Rev. Moses Hibbard of St. Nicholas Orthodox Church in Billings.
Early Christians followed the Hebrew custom of celebrating Easter the same day that Jews celebrated Passover, Hibbard said. On the Jewish lunar calendar, that was the 14th day of Nisan.
"Eventually down the road there was some early controversies over the dating, but that didn't break the church apart," he said.
Then came the Schism of 1054, which led to formation of the Roman Catholic and the Eastern Orthodox churches. While Roman Catholics eventually adopted the astronomically accurate Gregorian calendar, the Orthodox Church calculated Easter according to the less-accurate Julian calendar.
So, while all Christians in the northern hemisphere celebrate Easter on the first Sunday after the full moon of spring, the calendars they use to determine the date are different.
Oftentimes the two Easters are about a month apart, Hibbard said, with Orthodox Easter landing on the later dates when the two don’t mesh. This year the two coming together is slightly disappointing, he admitted.
“Usually Easter candy is on sale,” he said, smiling. “So we don’t get the benefit of that this year.”