The celebration date changes because it follows the lunar calendar. Easter always falls on the first Sunday after the full moon in the period from 22 March to 25 April.
Why this period?
It follows March equinox, the time of year when the Sun shines directly on the equator, making night and day nearly equal all over the world.
Ecclesiastically fixed on 21st March, the March equinox heralds the beginning of Spring, even though our Gregorian calendars date Spring from the beginning of March. March equinox has traditionally been celebrated as a time of rebirth or renewal, hence why in Christianity, Easter Sunday represents the resurrection of Christ.
Five quirky facts about Easter
1. The exquisite Fabergé eggs were invented in 1885 as Easter gifts for the Russian royal family to give to family and friends.
2. In early 1880s in parts of Germany, eggs were used as birth certificates. They were dyed, inscribed and decorated and could even be used as proof of identity in court.
3. The largest ever Easter egg hunt was in Florida, where 9,753 children searched for 501,000 eggs.
4. The name Easter is thought to come from the German goddess Eostre, whose name derives from Proto-Germanic meaning ‘dawn’.
5. As part of a Good Friday tradition, the English would hang a hot cross bun in the house for an entire year to protect the kitchen from fire and ensure perfect bread.