Easter Date Calculator
Calculate the exact date of Easter Sunday for any year between 326 and 4099 AD. Instant results with detailed algorithm explanation.
Easter Sunday Date
Upcoming Easter Dates
Everything You Need to Know About Easter Dates
Why Easter Dates Change Each Year
Easter is a moveable feast that doesn't have a fixed date in the Gregorian calendar. Its date is determined by a combination of solar and lunar cycles:
- Based on the first Sunday after the first ecclesiastical full moon following the vernal equinox
- The vernal equinox is fixed as March 21 for calculation purposes
- Easter can fall between March 22 and April 25
- Different Christian traditions use different calculation methods
Practical Information
- Earliest possible date: March 22 (last occurred in 1818, will next occur in 2285)
- Latest possible date: April 25 (last occurred in 1943, will next occur in 2038)
- Most common date: April 19
- Western vs. Orthodox Easter: Different calendars cause date differences
- Related holidays: Good Friday (2 days before), Easter Monday (day after)
The Easter Date Algorithm
Easter date calculation follows the Computus algorithm established by the Council of Nicaea in 325 AD. Here's the simplified method used by this calculator:
Calculate the Golden Number
Golden Number = (Year mod 19) + 1
This represents the position of the year in the 19-year Metonic cycle of the moon.
Determine the Gregorian Epact
A series of calculations accounts for solar and lunar corrections to synchronize the calendar with astronomical events.
Find the Ecclesiastical Full Moon
Based on the epact value, determine the date of the ecclesiastical full moon (which may differ from the astronomical full moon).
Calculate Easter Sunday
Easter Sunday = First Sunday after the ecclesiastical full moon date.
Gregorian Epact to Full Moon Date Reference
| Gregorian Epact | Ecclesiastical Full Moon Date | Gregorian Epact | Ecclesiastical Full Moon Date |
|---|---|---|---|
| 0 | April 13 | 15 | March 29 |
| 1 | April 12 | 16 | March 28 |
| 2 | April 11 | 17 | March 27 |
| 3 | April 10 | 18 | March 26 |
| 4 | April 9 | 19 | March 25 |
| 5 | April 8 | 23 | March 21 |
Based on the conversion table from the Easter calculation algorithm
Frequently Asked Questions
Easter is based on lunar cycles (specifically the first Sunday after the first full moon following the vernal equinox), unlike fixed-date holidays like Christmas. This connection to both solar (equinox) and lunar (full moon) cycles causes the date to vary.
Western Christianity uses the Gregorian calendar for Easter calculations, while Orthodox Christianity primarily uses the Julian calendar. Additionally, Orthodox traditions require that Easter must fall after Passover. These differences can cause the dates to be up to five weeks apart.
Easter dates can be reliably calculated for years 326 to 4099 AD using the established algorithms. Beyond that range, calendar reforms or astronomical changes may affect accuracy.