It was one of those falling-asleep moments in bed long ago, when my drowsy wife mumbled to me, “Is Easter two Sundays from now or three?” We had plans for a family gathering on Easter Sunday that would take some preparation, but that was at least two weeks away. Maybe three.
“Don’t know,” I mumbled. It had been a long, tiring day for both of us, and calendar considerations could wait until morning, to my way of thinking. “Does it really matter right now?”
I could feel her head nodding in affirmation on her pillow. “I won’t be able to sleep if I don’t know,” she said.
I had been married to her long enough by then to know that I wouldn’t be able to sleep until she knew, either. But the calendar was in the kitchen, a long, alertness-inducing walk away.
I sighed and pulled aside the curtain to peer out the window next to the bed. “Two Sundays,” I mumbled and, with the matter settled, closed my eyes to drift off.
My wife sat up in bed. “Well, if you don’t know, and if you don’t want to check the calendar, you don’t have to be a jerk about it.”
“I’m not being a jerk,” I said in my defense, one of those rare moments when I could say it and mean it. “I checked. It’s in two weeks. Look for yourself.”
Now she was out of bed, fully awake, walking around to my side to pull open the curtain for herself. “What, do you have a calendar taped to the window?”
“You could say that,” I said.
She gazed at the window, finding only the glowing light of a waxing gibbous moon in the clear night sky. “Very funny,” she said. I think she mumbled “Jerk” under her breath to punctuate it.
“No, really,” I said, and now I was awake. I sat up to explain something that I thought she already knew.
Religious considerations aside, there’s something special about Easter that makes it different from any other holiday, and all it takes is a glance out the window to see it.
Many other holidays — like Christmas, Independence Day or St. Patrick’s Day — always fall on the same calendar date, regardless of the day of the week. They’re the easiest to remember.
Other holidays — like Presidents’ Day, Memorial Day or Mothers’ Day — fall on the same day of the week at a certain time of month. Not too bad, as long as you know what month you’re in.
But not Easter. Easter is a floating holiday that might fall on any Sunday in a five-week span of time from late March to late April—March 22 to April 25, to be exact.
And the reason for its endless wandering — the calculation that makes Easter so special — is that it is the only holiday that is actually tied to the mechanics of the universe.
Let’s begin with the sun and the Earth. You can’t find Easter without knowing what the sun is doing as our planet whirls around it.
To determine when Easter will fall in any given year, first begin with the vernal equinox, the day in springtime when the sun crosses the plane of the equator, making days and nights of approximate equal length on the way to longer days in the northern hemisphere, and shorter days in the southern. With minor variation, that happens on March 21.
But knowing what dance the sun and earth are doing is only the start to finding Easter. You also have to know what’s going on with the moon.
Once the vernal equinox has passed, find the next full moon. It could be on the same day, or it could be as much as 28 days later.
Once you have found the first full moon after the vernal equinox, you’re almost there! Now find the first Sunday that follows. It could be the very next day if the full moon is on a Saturday, or if the full moon is on a Monday it could be as much as six days later.
That’s Easter: the first Sunday after the first full moon after the vernal equinox — a moveable feast that could happen anytime between March 22 and April 25.
Simple, right?
The reason why we arrived at that calculation is a bit obscure, and it took centuries to be determined and agreed to by all the churches in the Christian world, but the choice of that nomadic sun-moon date is related to the phase of the moon — and the position of the sun — under which Christ is believed to have died and was resurrected. Easter is calculated to be observed when those conditions realign every year.
And because it took the greatest minds of Christendom the better part of a millennium to figure it out, don’t expect me to explain it all here. You don’t want to hear me prattle on about Quartodeciman polycarps, embolismic months and Paschal moons. Anyone trying to give a full explanation would need at least until Christmas to get it in.
For now, just trust me — Easter this year is on Sunday, March 27.
If you don’t believe me, just look out the window.
And don’t lose any more sleep over it.
