Complicated Way the Date for Easter is Determined
I celebrate Easter, I grew up getting all dressed up to go to church, but I don't recall ever learning how the date of Easter was determined. Of course, I knew it changed dates but I didn't know why until today.
Are my co-worker and I the only people who didn't know about this? It was casually brought up in conversation: 'Why does Easter change dates? Who determines that?" Good question, so I Googled it and the first result that popped up I didn't believe. But then I kept looking and sure enough, it was true.
It turns out that the date of Easter is determined by the first full moon of spring. That's the simple version of it. I had no idea! When I first saw that answer I thought, 'Nah, why would the full moon be the determining factor in this?' I guess it's because the Jewish Passover is always celebrated on the first full moon of spring. TimeandDate.com says, "In 325 CE, the Council of Nicaea established that Easter would be held on the first Sunday after the first Full Moon occurring on or after the vernal equinox [aka after the first day of spring]."
Here's where it gets complicated. On our calendars, the first day of spring could be March 19th, 20th, 21st, or 22nd. In 2019, for example, our calendars said the first day of spring was Wednesday, March 20th and the first full moon of spring took place on Thursday, March 21st. So that means Easter was Sunday, March 24th, right? Wrong. The Church has one set date for the first day of spring and that date is March 21st. That's the date that's used to determine when Easter is. So when figuring out the date for Easter, it's the first Sunday after the first full moon after March 21st.