When is Easter 2020, and why does the date change each year?
TODAY is Easter Sunday, a time for Easter egg hunts and staying home with family.
But why does it change each year and when are the school holidays? Here's what you should know.
When is Easter 2020?
Unlike Halloween, Christmas and Valentine’s Day which all fall on fixed dates, Easter can be any time between March 22 and April 25.
In 2020 it is TODAY, Sunday, April 12.
Good Friday was therefore on April 10, and the Easter Monday bank holiday is on April 13.
The date is decided by a complex set of calculations based on observations of the moon.
How is the date of Easter decided and why does it change each year?
In Western Christianity, Easter Sunday must always follow the first full moon after the spring equinox.
Easter celebrates the death and resurrection of Jesus, which the Bible says happened around the Jewish festival Passover.
Passover typically begins on the night of the first full moon after the spring equinox, except in "leap months" when it is the second full moon, as in 2016.
In 2020 the full moon is on April 8, which is also the date Passover starts.
Because the precise timing of observing the full moon can vary in each time zone, the Church instead calculates the date from the ecclesiastical calendar.
This divides 19 normal calendar years into 235 months of 30 and 29 days each, with the ecclesiastical full moon on the 14th day of each lunar month.
The "paschal full moon" - from the Aramaic for Passover - is the one that falls on or after the spring equinox on March 21.
Easter Day is the first Sunday after the paschal full moon - so if the full moon is on a Sunday, Easter will be a week later.
Therefore the earliest Easter can be is March 22, and the latest is April 25.
The latest Easter in recent years was April 23 in the year 2000, and the earliest was March 23 in 2008.
It will not fall in March again until 2024 when it is on March 31.
In 1943 a full moon fell on March 20, just before the equinox, so the paschal full moon was the next one on April 18.
This was a Sunday so Easter was seven days later on April 25.
It will not be this late again until 2038.
Christians in the East use the Julian calendar, 13 days behind the Gregorian calendar used in the West, so the full moon and equinox are calculated according to a different date.
This means in 2020 the Eastern church will celebrate Easter on April 19, a week after Western churches.
Some years, such as in 2010, 2011, 2014 and 2017, the two churches celebrated Easter on the same day. This will happen next in 2025.
In other years the festivals may be up to five weeks apart, as happened in 2013 and 2016.