Date of Easter Astronomy Calculator

I have created the first Astronomy Calculator which is the Date of Easter.  The calculations are based on the book Practical Astronomy with you Calculator or Spreadsheet by Peter Duffett-Smith and Jonathan Zwart.

The method the authors showed in their book is based on a method devised in 1876 which was in Butcher’s Ecclesiastical Calendar.  The astronomical calculation is valid for all dates from 1583.