This year, Easter falls on April 5 — but, as those who celebrate the major Christian holiday will know, the day doesn’t stay in one place for long. Easter is one of the “moveable feasts,” a holiday that falls on a different calendar date each year. It’s calculated as the first Sunday after the first full moon on or after the vernal equinox.
Though the beginning of spring generally happens around the same time every year — the church uses March 21 as the date — the lunar calendar and the Gregorian calendar don’t match up, which means the timing of the full moon can change quite a bit. (This year, that full moon came on April 4.) Easter thus has about a month’s worth of time in which to move around.
That system worked for hundreds of years, but as Easter became not only a religious holiday, but also an occasion for sales, shopping and parades, the mobility of the fête began to cause a problem.
Stocking Easter goodies and planning projected profits is difficult to do when the calendar moves around, and even more so if you use Easter to mark the start of the whole shopping season. So in 1926, a group of storekeepers came up with a solution: fix the date. Not fix as in “make better”; fix as in “fix in place.”
As TIME explained on Feb. 1 of that year:
The church’s response to the proposal? “Clergymen,” TIME reported, “were vexed.” Nearly 90 years later we know that there was no need for such vexation: Though TIME didn’t follow up on the story, Easter is still moving around the same way it always has.