Overview
Introduction
Easter Sunday moves around the calendar every year, following a centuries-old ecclesiastical rule rather than a fixed date, which makes it easy to forget offhand.
This tool calculates the exact date for any year or range of years, using the same algorithm churches and calendar software rely on.
What Is Find Easter Dates?
An Easter date finder that computes Western (Gregorian) Easter Sunday for a single year or a span of years.
It implements the Anonymous Gregorian algorithm, a purely arithmetic method that reproduces the traditional "first Sunday after the Paschal full moon" rule without needing real lunar data.
How Find Easter Dates Works
The input year (or year range) is parsed and validated, then each year is run through the algorithm's sequence of modular arithmetic steps derived from the 19-year Metonic cycle and century-based corrections.
The result of those steps yields the month and day of Easter Sunday for that year, which is formatted as YYYY-MM-DD.
When To Use Find Easter Dates
Use it to plan events, holidays, or school calendars around Easter Sunday, or its related dates like Good Friday and Easter Monday.
It's also handy for testing calendar software that needs to compute correct holiday dates across many years.
Often used alongside Find Day of the Year, Generate a Date Sequence and Find Leap Years.
Features
Advantages
- Exact algorithmic calculation, not a lookup table, so it works for any supported year without needing pre-stored data.
- Supports batch calculation across a range of years in one pass.
- Uses the same well-documented algorithm found in astronomical and calendrical references.
Limitations
- Calculates Western (Gregorian) Easter only, not Eastern Orthodox Easter, which follows the Julian calendar.
- Limited to years 1583 through 9999, matching the Gregorian calendar's adoption and the algorithm's valid range.
Examples
Best Practices & Notes
Best Practices
- Use a single year when you only need one date; ranges are best kept to what you actually need, since very long spans produce long lists.
- Remember that Good Friday is 2 days before, and Easter Monday is 1 day after, the Easter Sunday date this tool reports.
Developer Notes
The implementation follows the Anonymous Gregorian algorithm exactly as commonly published (variables a through m derived from `year % 19`, `year / 100`, and related modular steps), producing a month/day pair directly without floating-point date arithmetic or lunar tables, which keeps it exact and fast even across large year ranges.
Find Easter Dates Use Cases
- Planning school, church, or corporate calendars around Easter weekend
- Testing calendar or scheduling software's holiday-date logic
- Looking up Easter's date for a specific past or future year
Common Mistakes
- Assuming this returns Eastern Orthodox Easter, which can fall on a different date calculated from the Julian calendar instead.
- Entering a year before 1583, which predates the Gregorian calendar this algorithm assumes.
Tips
- Combine with Date Sequence Generator if you need a run of dates relative to a computed Easter Sunday, like the surrounding Holy Week.
- Check Day of Year Finder on the result to see how far into the year Easter falls.