An interesting sidelight to the date of Easter in the early Christian church, and one of the most divisive and contentious subjects, related to the date of Passover. Passover was not as well defined back then. The beginning of each lunar month was declared by a committee appointed by the Sanhedrin based on the physical observation of the first crescent moon. The choice of which lunar month represented the beginning of spring was based on crude observation of such things as the state of vegetation; the astronomical event of the vernal equinox was not a consideration. We will never know whether the Crucifixion was in March or April because no one noted if that year was warm and wet or a cool, dry one.
The death of Jesus was originally observed on Nisan 14 and Easter was celebrated three days later (particularly in the east) regardless of the day of the week on which it fell. In the west, Easter was generally (but not always) celebrated on a Sunday . The supporters of the eastern practice became known as quartodecimians due to their adherence to Nisan 14 and the supporters of Easter Sunday became known as quintodecimians. Since the time of Passover was determined empirically, the quartodecimians had to ask Jewish authorities when Passover began in order to know when to celebrate Easter. To many church leaders, the quartodecimians represented an unacceptable dependence on Jewish customs that had to be eliminated (the so called "quartodecimian heresy"). This was a major motivation for the First Council of Nicea (AD 325). The Nicean Council did not define a method for determining the date of Easter but said only that it should be celebrated on Sunday. The practice of using the vernal equinox to define the beginning of spring originated with the bishops of Alexandria (probably using the resources of the great library). The method of using the Metonic cycle to predict when the Paschal moon would occur also originated in Alexandria and this lunar cycle is still known as the "Alexandrine cycle" in church literature. The process of determining the date of Easter was far beyond the capabilities of all but the most learned and the practice of paschal letters from the Pope originated to ensure that all Christians celebrated Easter at the same time. Summary: Discussions concerning the date of Easter are not new. Footnote: Nisan, the month of new grain, is the seventh month of the Jewish year in the current Jewish calendar but it was not always so. According to the Mosaic law, Abib, the month the Israelites came out of Egypt, would be the first month of the year and Passover would be celebrated during Abib. Abib was probably in about April. After the captivity in Babylon, the names of the months were changed to names of Chaldean origin and Nisan became the first month. Also, the civil year was changed to begin at the start of Tishri and Nisan became the seventh month, although Nisan is still the start of the Jewish ecclesiastical year. James E. Morrison Astrolabe web pages at: http://myhouse.com/mc/planet/astrodir/astrolab.htm
