Astronomical vs. Ecclesiastical Dates
In years in which the church's March equinox and Paschal Full Moon dates do not coincide with the astronomical dates of these events, confusion about the date of Easter can arise. In 2019, for example, the March equinox in the Western Hemisphere
happened on Wednesday, March 20, while the first Full Moon in spring
was on Thursday, March 21 in many time zones. If the church followed the timing of these astronomical events, Easter would have been celebrated on March 24, the Sunday after the Full Moon on March 21.
However, the Full Moon date in March specified by the church's lunar calendar, also called the
ecclesiastical Full Moon, was March 20, 2019—one day
before the ecclesiastical date of the March equinox, March 21. For that reason, the Easter date 2019 is based on the
next ecclesiastical Full Moon, which is on April 18. This is why Easter 2019 falls on April 21.
Calendar with holidays
Earliest and Latest Easter Dates
According to the Metonic cycle, the Paschal Full Moon falls on a recurring sequence of 19 dates ranging from March 21 to April 18. Since Easter happens on the Sunday
following the Paschal Full Moon, it can fall on any date between March 22 and April 25 (years 1753-2400).
List of years with earliest and latest Easter dates