The problem of finding the date of Easter is not an easy one. The date depends on both the Gregorian calendar (in which there is a leap year every four years, except for century years where only one in every four is a leap year) and the Jewish calendar (which follows a solar cycle for years and lunar cycle for months - it has a 19-year cycle in which the 3, 6, 8, 11, 14, 17 and 19 years have a thirteenth month).

In the Bible (St. Luke, Chapter 22) we have a description of how Jesus ate the Passover with his disciples before going to Gethsemane. The Last Supper, the Agony in the Garden and the Crucifixion were at the time of the full moon following March 21st (Spring Equinox). The hurry to remove the body from the cross before the beginning of the Jewish Sabbath (Saturday) fixes the Crucifixion on a Friday.

The Church has sought to preserve this sequence. In 1961, T O'Beirne published in the journal New Scientist an algorithm called TEN DIVISIONS to EASTER for finding the Easter date for any year.

Algorithm to find the date of Easter for any year.

To use the the algorithm below, simply select the year you want to find the date of Easter for and then carry through the calculations as shown in the algorithm. Note that where the answer to a division is needed, you only want the whole number part, not any decimals. The remainder is what is left over after a division once the number as been split into as many whole parts as possible.