Easter moves every year, and the Orthodox and Catholic churches often celebrate it on different dates. Enter a year and this tool works out both — the Orthodox date (Vaskrs) and the Western date used by Catholics and Protestants — and tells you how far apart they are. Everything is calculated in your browser.
Orthodox Easter
Sunday, April 12, 2026
Both dates are shown on the Gregorian (civil) calendar.
How it works
Easter is the first Sunday after the first full moon on or after the spring equinox. The churches compute this with a rule-based table (the computus) rather than real astronomy, so the date is fixed and predictable centuries ahead. This tool uses the standard Meeus algorithms for both traditions.
The difference comes from the calendar each church uses. The Western date is figured on the Gregorian calendar; the Orthodox date is figured on the older Julian calendar and then shown here on the Gregorian calendar you read day to day — which currently shifts it 13 days later in the reckoning.
Because the two methods use different equinox and full-moon rules, Orthodox Easter is the same day as Western Easter in some years and up to five weeks later in others. It is never earlier. The calculator is valid for years 1583 onward, when the Gregorian calendar began.
Practical examples
A year they coincide (2025)
Enter 2025 and both fall on 20 April — one of the years the two calendars line up, so everyone celebrates on the same Sunday.
A year they diverge (2024)
Enter 2024: Catholic Easter is 31 March while Orthodox Easter is 5 May — a gap of five weeks, the maximum the two can differ.
Planning ahead (2026)
Enter 2026 to see Catholic Easter on 5 April and Orthodox Easter on 12 April, one week apart — useful for scheduling travel, work leave or family gatherings.
Frequently asked questions
Why does the date of Easter change every year?
Unlike Christmas, Easter is tied to the moon: it is the first Sunday after the first ecclesiastical full moon on or after 21 March. Because lunar and solar cycles do not line up neatly, the date drifts across late March to late April (or May for the Orthodox reckoning).
Why do Orthodox and Catholic Easter differ?
The two churches use different calendars to compute it. The West uses the Gregorian calendar and equinox; the Orthodox Church uses the older Julian calendar. The gap between the calendars, plus different full-moon tables, pushes Orthodox Easter to the same day or up to five weeks later.
Can Orthodox Easter ever be earlier than Catholic Easter?
No. Because of the Julian calendar’s later reckoning, Orthodox Easter falls on the same Sunday as Western Easter or after it — never before.
What is the computus?
It is the set of rules the church uses to calculate Easter’s date from tables of the moon’s phases and the day of the week, rather than from live astronomical observation. This tool implements the well-known Meeus versions of it.
What is the earliest and latest Easter can fall?
By the Western rule Easter ranges from 22 March to 25 April. The Orthodox date, shown on the Gregorian calendar, can fall as late as early May because of the calendar offset.
Which years can I calculate?
Any year from 1583 to 4099. The lower bound is when the Gregorian calendar was introduced in 1582; before that the Gregorian rule does not apply.
How do I find Good Friday or Pentecost from this?
Count from Easter Sunday: Good Friday is two days before, Palm Sunday one week before, Ascension 39 days after, and Pentecost 49 days after. Use the Add or Subtract Days tool to shift the Easter date by those amounts.
Is the Orthodox date shown on the Julian or Gregorian calendar?
On the Gregorian calendar — the everyday civil calendar. The underlying calculation is Julian, but the result is converted so the date matches your normal calendar and phone.
Does the calculation happen online?
No. The whole computus runs in your browser with no server call, so it works offline once the page has loaded, and nothing you enter is sent anywhere.
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