Ecclesiastical full moon century AD computists of some churches, among which were the Church of Rome and the one of Alexandria, had begun to calculate their own periodic sequences of dates of paschal full moon, to be able to determine their own dates of Easter Sunday. The motivation for these experiments was a dissatisfaction with the Jewish calendars that Christians had hitherto relied on to fix the date of Easter. These Jewish calendars, according to their Christian critics, sometimes placed Nisan 14, the paschal full moon and the day of preparation for the Jewish Passover, before the spring equinox (see Easter). The Christians
March equinox March equinox The March equinox or Northward equinox is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox is known as the vernal equinox in the Northern Hemisphere and as the autumnal equinox in the Southern. On the Gregorian calendar, the Northward equinox can occur as early as 19 March or as late as 21 March. For a common year the computed time slippage is about 5 hours 49 minutes "later" than the previous year, and for a leap year