Another factor which figures prominently in determining the date of Pascha is the date of Passover.Originally, Passover was celebrated on the first full moon after the vernal equinox.Events in Jewish history contributing to the dispersion of the Jews had as a consequence a departure from the way Passover was reckoned at the time of our Lord's death and resurrection.This caused the Passover to precede the vernal equinox in some years.The long-awaited common celebration of Pascha on April 15, 2001 by all Christians has come and gone.It was in 1990 when this coincidence last occurred and will be in 2004 when it occurs again.In anticipation of this common observance by all Christians, much was said and written.
This assurance lasted, however, only for a short time.
Thus, the Council of Nicaea sought to link the principles for determining the date of Pascha to the norms for calculating Passover during our Lord's lifetime.
Despite the intervention of Nicaea, certain differences in the technicalities of regulating the date of Pascha remained even thereafter.
Depending upon the number of years in the cycle, the full moon occurred on the same day of the year as at the beginning of the cycle with some exceptions.
The more accurate the cycle, the less frequent were the exceptions.