Why do Easter's dates change every year?

As the days get longer and the flowers start blossoming to give us a glimpse of spring, many of us begin to ponder a familiar question: “when is Easter this year?”

For such a widely recognised holiday, it might seem strange for Easter to fall on inconsistent dates. Of course, some holidays, like Christmas and New Year’s Day, occur on the same date each year, while others follow clear rules—for example, the Early May Bank Holiday and Spring Bank Holiday fall on the first and last Mondays of May respectively. Why does Easter go against the grain?

Never fear, we’ll explain everything you need to know about why Easter is celebrated, and why its dates change each year. We’ll even provide you with the Easter dates for your diary for the rest of the decade!

In case you’ve forgotten, Easter is the Christian celebration of Jesus’s resurrection. The Thursday before Easter Sunday is known in England as “Maundy Thursday” (“Holy Thursday”) and is believed to be when Jesus and His disciples ate bread and drank wine in the Last Supper.

Good Friday commemorates Jesus’s crucifixion (the name derives from an obsolete meaning of “good”, meaning “holy”), and Easter Sunday marks His resurrection. Easter Monday celebrates the 40 days in which Jesus is believed to have stayed on Earth before ascending to heaven.

Easter’s dates change each year because it is calculated using the Moon. Easter falls on the first Sunday after the Paschal Full Moon, which is the first full moon that occurs after the spring equinox. The spring equinox transpires when the sun is directly above the equator—in the Northern Hemisphere, this marks the beginning of springtime.

The complexity of using the lunar calendar, which tracks the Moon’s phases, to calculate Easter is that it does not fully align with the Gregorian calendar we use in the UK, which is based on the Earth’s orbit around the sun (ie, the solar calendar). While the Gregorian calendar is normally 365 days (366 this year!), the lunar calendar is approximately 354 days, meaning the date can shift.

To calculate Easter, the spring equinox is presumed to occur on March 21, meaning that Easter can fall anywhere between March 22 and April 25. The Bible’s New Testament indicates that Jesus was crucified and resurrected at around the time of the Jewish festival of Passover; the date for this is also calculated using the lunar calendar.

However, even this decision varies based on the calendar used. Eastern Christian bodies like the Eastern Orthodox Church use the Julian calendar—devised by Julius Caesar—rather than the Gregorian calendar to calculate Easter. This means that, in some countries, Easter can fall as late as May 8!

These are the Easter dates you need to know from 2025 to 2030. Note that these are the dates recognised in the UK: in other countries, they may differ.