Curious Questions: Why does Easter move dates every year?

Phoebe Bath researches why exactly Easter is a called a 'moveable feast'.

Ah, Easter. For most of us, we are far too busy inhaling chocolate bunnies and delicious eggs to stop and consider why it is that the date of Easter changes. As long as hot cross buns are flooding supermarket shelves, newborn lambs are frolicking in the fields and the daffodils have unfurled their golden heads, that’s all that really matters.

But have you ever stopped to wonder why Easter Sunday can fall anywhere between March 22nd and April 25th? Putting the chocolate firmly to one side, I decide to find out more about this Christian ‘mystery.’

Determining the exact date of Easter has long been contested, even since the advent of the church. Jesus’ followers themselves failed to record the exact date of his resurrection, making the matter of deciding upon a date all the more tricky. Reading on, I learn that there is, in fact, a very simple explanation amidst the confusion: Easter is what’s known as a ‘movable feast’.

The earliest believers in the church wished to keep Easter correlated to the Jewish Passover, and as the death, burial of Jesus happened after the Passover, followers and believers wanted Easter to remain a celebration that occurred after Passover. Given that the Jewish calendar is based on solar and lunar cycles, the dates shifts from year to year, subsequently causing the dates of Easter to shift, too.

Gothic Moon. Image shot 11/2005. Exact date unknown.

Today, in modern Western Christianity, Easter is celebrated on the Sunday that follows the Paschal Full Moon date of the year, which is determined from historical tables, meaning the date of Easter no longer directly corresponds exactly to lunar events.

Interesting stuff.

What’s more, as astronomers were able to roughly establish the dates of all future full moons, the Western Church used these calculations to create a table of Ecclesiastical Full Moon dates: these dates then determine the Holy Days on the Ecclesiastical calendar.

Whilst munching on my buttered hot cross bun, I decide that the origins of Easter hold a fascination that should be widely acknowledged, and its powerful history is certainly something I’ll be thinking of whilst Easter hymns ring in the air come Sunday.