Ukraina sex date - Easter dating method
Astronomically, the begin of spring is not a day but the single moment at which the Sun passes the equatorial plane from South to North.
In about 3 of every 4 years this is on 20 March, and on average that is somewhere around 20.75 March.
This PFM may differ from the real full moon by a few days and it may even differ from the astronomical first full moon in spring by an entire month, an event that is called an Easter paradox. 525 by Dionysius Exiguus (who also and at the same time introduced the Anno Domini year counting that we still use today) in his Liber de Paschate (for an English translation click here, see alsy my Dutch translation).
These calculations are only based on integer days, the time-of-day is ignored. This Easter dating method introduced by Dionysius is called the Julian method, since it is based on the Julian calendar.
The Jews celebrate the exodus from Egypt (which was a true liberation) every year on 15 Nisan, which is called Pesach (meaning passover).