Easter is celebrated on March 22nd; no, make that April 1st. The truth is Easter is celebrated anywhere between March 22 and April 25. And Christians do not all celebrate it on the same day. Confusing? It has been since the advent of Easter which is thought to be in the first century.
There was no decision made within the second century church about exactly when Easter should be celebrated. The early Christians celebrated the resurrection of Jesus on Passover which was the fourteenth day of Nisan, the first month of the Jewish year. But by the end of the second century some churches continued to celebrate on Passover regardless of what day of the week it was, and others observed Easter on the first Sunday after Passover. But if Passover fell on a Sunday, then Easter’s observance would not happen for seven days after it. So Easter was observed somewhere between the 15th and 21st day of Nisan.
Finally the date of Easter was agreed to be the first Sunday after the full moon on or after the vernal equinox on March 21st. This did not reach harmony in the church either.
Local differences in determining the date of Easter/Pascha remained even after Nicea 6 Council in the 6th century. The Council used calculations based on Alexandrian astronomers’ and scholars’ findings. Things looked better for harmony within the church and the date for Easter gained universal acceptance.
The Celtic Church did not postpone Easter when Passover occurred on a Sunday. They celebrated it on the 14th to the 21st day of Nisan. About one year in seven, their observance would fall one week before the Roman church’s Easter.
Now here’s the rub. The Julian calendar, used by the entire Christian Church until the mid 16th century was in error about 11 minutes and 14 seconds each year. This accumulated to be a full day error every 128 years. By the late 16th century, the error had spread to ten days. Pope Gregory XIII commissioned a study to decide what to do about this problem.
The solution the study came up with sounds incredibly complex. They decided to make most years into non-leap years. Only those years which were evenly divisible by 400 were to be leap years. It’s elementary: Roman Catholic countries corrected the calendar by making October 15, 1582 CE follow October 4, 1582 CE. Got that?
England put off the adoption of the Gregorian calendar until the mid 18th century. They had to make an eleven day correction, making the day following September 2, 1752 be September 14th.
Eastern Orthodox Churches still use the Julian calendar. Currently, it is 13 days later than the Gregorian calendar. Since 1923, the Romanian Orthodox and Greek Orthodox Churches have adopted the Gregorian calendar. However, (are you ready for this?), they continue to use the Julian calendar for calculating Easter. The gap this creates causes Easter to be celebrated on the same Sunday as the Roman Catholic ad Eastern Orthodox Churches only about once every three or four years.
Do you think that Christian unity prevailed and all was well with the date for Easter? Think again. It remained a point of contention. The ancient dispute over the date still goes on in the 21st century. Churches are taking a new look at the theological issues that have divide them in an effort to increase unity. Isn’t it a wonder that so many can agree to believe in the same God with the mess their division has made on a simple thing like when to observe Easter? The need for a common date in all of the Christian Churches continues today.