# Date of Easter

The real purpose of this page is to show that I can still write programs! It contains a program I have written in Java (see Sun's Java site) to calculate the date of Easter Sunday in any given year.
## Java Applet to calculate date of Easter

Easter.java is the source for the Applet.

## Algorithm used to calculate date of Easter

The algorithm is taken from the 1662 book of Common Prayer of the Church of England, as revised in 1953 (there was a transition from the Julian to the Gregorian calendar in 1752). Specifically it says:

"A TABLE TO FIND EASTER DAY,

FROM THE PRESENT TIME TILL THE YEAR 2199 INCLUSIVE,

ACCORDING TO THE FOREGOING CALENDAR".
This Table contains so much of the Calendar as is necessary for the determining of *Easter*; to find which, look for the the Golden Number of the Year in the First Column of the Table, against which stands the Day of the Paschal Full Moon; then look in the Third Column for the Sunday Letter, next after the Day of the Full Moon, and the Day of the Month standing against that Sunday Letter is *Easter-Day*. If the Full Moon happens on a Sunday, then (according to the First Rule) the next Sunday after is Easter Day.

To find the Golden Number, or Prime, add One to the Year of our Lord, and then divide by `9; the Remainder, if any, is the Golden Number; but if nothing remaineth, then 19 is the Golden Number.

To find the Dominical or Sunday Letter,according to the Calendar, until the year 2099 inclusive, add to the Year of our Lord its Fourth Part, ommitting fractions, and also the number 6: Divide the Sum by 7; and if there is no Remainder then A is the Sunday Letter: But if any Number remaineth, then the Letter standing against that Number in the small annexed table is the Sunday Letter.

For the following Century, that is from the Year 2100 until the Year 2199 inclusive, add to the current Year its Fourth Part, and also the number 5, and then divide by 7, and proceed as in the last Rule.

Author: Paul Hardy