International Transgender Day of Visibility is an annual event occurring on March 31
Easter is an annual event occurring on a Sunday decided by an astronomical calculation.
................ The first Sunday after the full Moon that occurs on or after the spring equinox. If the full Moon falls on a Sunday then Easter is the next Sunday.
Standardisation
Up to the 8th century AD, there was no uniform method for determining the date of Easter, but the method favoured by the Council of Nicaea in AD 325 gradually became the accepted method. The adoption of the Gregorian calendar requires some modifications to this scheme but it is still basically the same. Not Correct
Unfortunately this simple definition is not strictly speaking correct. The spring or vernal equinox used is not the true equinox but an artificial one always assumed to be on 21 March. The full Moon used is not the true full Moon but an artificial construct based on the Metonic cycle. The reasons for this are that the method is then independent of longitude on the Earth and is thus independent of time zone. It also allows the date of Easter to be calculated in advance regardless of the actual motion of the Earth around the Sun.
Which Easter? The method quoted here is valid for the determination of the date of Easter in Western Christian churches; the date used by the Eastern churches can be one, four or five weeks later.
