What has the full moon got to do with Easter?

Quite a lot! The date of Easter is actually determined by the full moon. Quite contrary to Christmas, the Easter date is part of the changing holidays and defined as follows: “Easter is on the Sunday after the first full moon in spring.”

At first glance, this appears to be quite easy: one look at the calendar, beginning of spring is mostly on 21st March and then simply search for the next full moon and the weekend after will be Easter.

Example for 2024
Beginning of spring: Wednesday, 20th March 2024
First full moon in spring: Monday, 25th March 2024
Easter: Sunday, 31st March 2024

Upon close inspection however, it is rather more complicated. On the one hand, the beginning of spring could fall astronomically on 19th, 20th or 21st of March, but for calculation purposes, a fixed date is used, being 21st March. On the other hand, there are various exceptions in the computation that will reflect the so called ‘Easter paradox’ in certain years, namely always, when Easter takes place on a date that goes against the original rule.

Anyhow, it is good to know the interval in which the Easter date has to fall: the earliest possible Easter date is 22nd March (will happen next in 2285), the latest possible Easter is the 25th April (will happen next in 2038).

But the real interesting question is, why this Easter date has been defined as a changing holiday rather than a fixed date? We remember to have read (confirmations or objections are welcome!) that the connection was to try and prevent a solar eclipse occuring on Good Friday, as this would have been associated in the past with fear, Armageddon and gloom. By defining Easter in “one week after full moon at the latest”, it could be eliminated because a solar eclipse can only take place at new moon, just like a lunar eclipse can only occur at full moon.

Enough of theory now … wishing you a happy Easter! 🙂

2024
Beginning of spring: Wednesday, 20th March 2024
First full moon in spring: Monday, 25th March 2024
Easter: Sunday, 31st March 2024

2023
Beginning of spring: Monday, 20th March 2023
First full moon in spring: Thursday, 6th April 2023
Easter: Sunday, 9th April 2023

2022
Beginning of spring: Tuesday, 20th March 2022
First full moon in spring: Saturday, 16th April 2022
Easter: Sunday, 17th April 2022

2021
Beginning of spring: Tuesday, 20th March 2021
First full moon in spring: Sunday, 28th March 2021
Easter: Sunday, 4th April 2021

2020
Beginning of spring: Tuesday, 20th March 2020
First full moon in spring: Wednesday, 8th April 2020
Easter: Sunday, 12th April 2020

2019
Beginning of spring: Wednesday, 20th March 2019
First full moon in spring: Thursday, 21st March 2019
Easter: Sunday, 21st April 2019 (!)
(This is a so called “Easter paradox”.)

2018
Beginning of spring: Tuesday, 20th March 2018
First full moon in spring: Saturday, 31st March 2018
Easter: Sunday, 1st April 2018

2017
Beginning of spring: Monday, 20th March 2017
First full moon in spring: Tuesday, 11th April 2017
Easter: Sunday, 16th April 2017

2016
Beginning of spring: Sunday, 20th March 2016
First full moon in spring: Wednesday, 23rd March 2016
Easter: Sunday, 27th March 2016

2015
Beginning of spring: Friday, 20th March 2015
First full moon in spring: Saturday, 4th April 2015
Easter: Sunday, 5th April 2015

2014
Beginning of spring: Thursday, 20th March 2014
First full moon in spring: Tuesday, 15th April 2014
Easter: Sunday, 20th April 2014

2013
Beginning of spring: Wednesday, 20th March 2013
First full moon in spring: Wednesday, 27th March 2013
Easter: Sunday, 31st March 2013

2012
Beginning of spring: Tuesday, 20th March 2012
First full moon in spring: Friday, 6th April 2012
Easter: Sunday, 8th April 2012

2011
Beginning of spring: Monday, 21st March 2011
First full moon in spring: Monday, 18th April 2011
Easter: Sunday, 24th April 2011