When is the Greek Orthodox Easter?
A lot of half-truths and errors circulate regarding the calculation of the date of Easter. In particular, the difference between the date of Easter in the Western Church and the Orthodox one is often not clear. In any event, to counter the rumours often spread, there is no simple rule according to which, for instance, the two Easter Sunday dates coincide every nth year. So when is Easter, actually?
Definition of the date of Easter
Easter Sunday is by definition the first Sunday after the first full moon of spring. This full moon is the “Easter limit” (terminus paschalis, Easter full moon, spring full moon, ecclesiastical full moon/EFM).
The start of spring
According to the Gregorian calendar, spring starts, as is well known, on 21 March but the Orthodox calculation is based on the Julian calendar. And now it becomes interesting: Although spring also starts on 21 March in the Julian calendar, 21 March does not fall on 21 March but currently about 13 days later. In fact, the Julian calendar limps behind the Gregorian one because it ignored the 1582 calendar reform by Pope Gregory VIII. So to be precise, the Greeks use two calendars in parallel, the “normal” Gregorian calendar for the secular sphere (since 21 March is the same day in Berlin and Athens), and the Julian calendar for their Orthodox Easter festival. Finally, it is then up to the full moon whether Easter is nevertheless celebrated at the same time or whether the Greeks do so later.
Spring full moon / Easter full moon
But it’s still more complicated than that because the difference in Easter dates cannot be explained every year by a different date for the start of spring alone, which is in turn due to the temporal shift between the Gregorian and Julian calendars. In fact, the Orthodox calculation also uses the Julian calendar to determine the phases of the moon. This Orthodox, Julian lunar calendar is also different. It is not identical to the progress of the moon that we can observe in reality in the sky!
|Western Church||Eastern Church|
|2018||1 April||8 April|
|2019||21 April||28 April|
|2020||12 April||19 April|
|2021||4 April||2 Mai|
|2022||17 April||24 April|
|2023||9 April||16 April|
|2024||31 March||5 May|
|2026||5 April||12 April|
|2027||28 March||2 May|