Easter
the Christian festival
Easter is the annual Christian festival celebrating the resurrection of Jesus Christ, after his execution on Good Friday. The time of the festival was fixed by the Council of Nicea in 325, since when it has been on the first Sunday after the Paschal full moon. The Paschal full moon being the full moon which falls on or first after 21st March - the vernal equinox. Using this method Easter Day will not fall before 22nd March and cannot fall after 25th April. But beware this moon is a theoretical one, the calculated date may not always agree with the astronomer's.
Calisto's main window indicates in red the date of Easter in England for every year
between 326 and 2999. In 1752, when England changed from the Julian to the Gregorian calendar, the date of Easter Day
was calculated for the Julian calendar after which the Gregorian method was used.
If you click on a date in Calisto's main window you will "drill-down" to the comparator (illustration on right) not only allows direct comparisons between dates in different countries, but also shows the dates of other Easters. Easter day in England is always shown with a red E. Before 1752 a blue E shows the Gregorian Easter, already being used in much of Europe between 1582 and 1752. After 1752 a blue E indicates Easter in countries still using the Julian calendar - mainly Orthodox Christian countries. The extract shown here also indicates the full moon on 22nd March and the vernal (spring) equinox, shown with a V.
The bible says that Jesus Christ was crucified during the Jewish festival of Passover week, which starts on the 14th day of Nissan. Because Jewish months always start with a new moon the full moon will occur around the 14th day of each month. The Paschal full moon, which is used to calculate Easter, is the same moon seen at the Jewish Passover.
