This was an alternative to calculating Pascha by the Passover and consisted in the creation of so-called "paschal cycles." Each paschal cycle corresponded to a certain number of years.
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.
330) and Canon 7 of the Holy Apostles (late 4th century) of those who celebrate Pascha "with the Jews." The purpose of this condemnation was to prevent Christians from taking into account the calculation of Passover in determining the date of Pascha.
Most Christians eventually ceased to regulate the observance of Pascha by the Jewish Passover.
If the full moon happens to fall on a Sunday, Pascha is observed the following Sunday.
The day taken to be the invariable date of the vernal equinox is March 21.
What was stressed was the need to keep alive the momentum of the occasion.
Unless we all understand the significance of this event, it will remain nothing more than a peculiarity of the calculations related to the date of Pascha. But in another sense, it is the convergence of all that we as Christians in the East and West profess regarding the centrality of the Resurrection of Jesus Christ as the cornerstone of our faith.
Christians, therefore, celebrated Pascha according to the same calculation-that is, on the first Sunday after the first full moon following the vernal equinox.
Their purpose, of course, was to preserve the original practice of celebrating Pascha following the vernal equinox.