Here’s a lesson I prepared for my RCIA class a few years ago:
The Date of Easter
The date of Easter has been an issue of some contention throughout the history of Christianity. Most of the issues are related to two items:
• Use of different calendars to observe the passing of time (lunar vs. solar years)
• Whether the feast was to occur on the date commemorating the Paschal Feast of
our Lord, or of His Resurrection
The list below shows the months of the lunar calendar and their modern calendar equivalents. Note the addition of Adar II, an invention of Jewish scholars to compensate for the fact that there are 12.4 lunar years in a solar year. This second Adar is inserted approximately every third year to compensate for this issue.
Lunar Month Length Solar Calendar Equivalent
- Nisan 30 days March-April
- Iyar 29 days April-May
- Sivan 30 days May-June
- Tammuz 29 days June-July
- Av 30 days July-August
- Elul 29 days August-September
- Tishri 30 days September-October
- Cheshvan 29 or 30 days October-November
- Kislev 30 or 29 days November-December
- Tevet 29 days December-January
- Shevat 30 days January-February
- Adar 29 or 30 days February-March
- Adar II 29 days March-April
Two different traditions developed in the ancient Church on the day of observing Easter:
• Those that observed Easter on the 14th of Nisan (the first Spring month in the Jewish
calendar) regardless of the day of the week – these persons were called
*Quartodecimans *
• Those that transferred the feast to the Sunday following the 14th of Nisan
Because of anomalies in the Jewish lunar calendar, it is possible for the 14th of Nisan to occur before the Vernal Equinox, which complicated matters even more. At the Council of Nicea (325) the issue of the date of Easter was discussed and the following guidelines agreed to:
• Easter was to be on a Sunday
• Following the vernal equinox
• After the 14th of Nisan
Accordingly, the manner of determining the date of Easter is:
• Easter is the first Sunday which occurs after the first full moon following the 21st of
March. This makes the earliest possible date March 22 and the latest April 25.
More info is available from the Old Catholic Encyclopedia, too.
God bless,