Why Does Easter Move Around So Much? LBC Explains

Why does Easter move around so much? In 2019, it's almost a month later than in 2018 - why?

Question

Why does Easter move around so much? In 2019, it's four weeks later than in 2018.
Chelsea, Brentwood

Answer

** Definitive **
Name: Tim, Feltham
Qualification: I got the answer from a nun
Answer: Easter is set based on the spring equinox and the moon. Easter Sunday is always the Sunday after the first full moon after the vernal equinox - which is when night and day are the same length.

Name: Tristan, Plumstead
Qualification: I was told this at school
Answer: It's the first Sunday after the fourth full moon of the year. Hence the reason Easter can move around by up to four weeks. In olden times, the calendar was based on the 28-day cycle of the moon, so that was how they measured it.