Eastern Orthodox churches use the Julian calendar, which can place the date of Easter anywhere between April 4 and May 8 when it's converted back to the Gregorian calendar.

The Julian calendar is about 13 days behind the Gregorian calendar. The dates were similar in 2010, 2011, 2014, 2017 and 2025. What is the earliest possible day for Easter?

Here's when Easter Sunday and Passover 2025 are and why they fall "late" this year. ... The Eastern Orthodox Church uses the Julian calendar, a solar calendar that was used by the Roman Empire.

Why has the Easter date been different? In 46 B.C., Julius Caesar established the Julian calendar. While similar to the now-standard Gregorian calendar, the Julian calendar had its flaws.

The Julian calendar falls a little further behind the Gregorian each year − it's lost 13 days since the Council of Nicaea − but the Orthodox Church still uses it for liturgical purposes.

Eastern Orthodox churches use the Julian calendar, which can place the date of Easter anywhere between April 4 and May 8 when it's converted back to the Gregorian calendar.

The Gregorian calendar, instituted by Pope Gregory XIII, went into effect in 1582. In the 1,417 years from 1583 through 3000, it’s most common for Easter to fall on April 16, with 61 instances.

Easter is determined by the calendar year. The dates differ because most Christians use the Gregorian calendar, originally introduced in 1582, while the Eastern Orthodox Church uses the Julian ...

The Gregorian calendar, instituted by Pope Gregory XIII, went into effect in 1582. In the 1,417 years from 1583 through 3000, it’s most common for Easter to fall on April 16, with 61 instances.

So, while using the Gregorian calendar results in a more accurate Easter date, Figel believes, separated Orthodox Churches are resistant to change, as the Julian calendar is part of their tradition.