TODAY is Easter Sunday, the first time the holiday has fallen in March in eight years.

Of course, we all know Easter is the biggest date in the Christian church's calendar celebrating the Resurrection of Jesus Christ. 

But what is probably less known is how the date for Easter is calculated.

Many people may have the vague notion that it is something to do with the Moon or the church's calendar.

So, why does Easter move each year and how is this decided?

How is the date of Easter set?

Easter Sunday generally falls on the first Sunday after the first full moon on or after the vernal (or 'Spring) equinox.

The 2024 equinox was on March 20, the 'beginning of spring' for the Northern Hemisphere. The first full moon after this was March 25, hence Easter is the following Sunday, March 31.

The Council of Nicaea, which was the first ecumenical council of the Christian Church, established the date for Easter when it met in the year 325 AD. There are 35 possible dates on which Easter Sunday can take place.

The earliest it can possibly fall is March 22 and the latest April 25.

Easter can never be any earlier as, by ecclesiastical rules, the vernal equinox is fixed on March 21, even though every March equinox after 2007 this century will be on March 19 or 20.

The last time Easter fell on March 22, the earliest possible date, it can be, was in 1818. The next time will be in 2285.

 The 21st Century's latest Easter will be in 2038, on April 25, with the next on that date not until 2190.