=DATE(A2,3,29.56 0.979*MOD(204-11*MOD(A2,19),30) - WEEKDAY(DATE(A2,3,28.56 0.979*MOD(204-11*MOD(A2,19),30)))) This is the Gerhardt Somitsch formula and is accurate from 1900-2203. =FLOOR("5/"&DAY(MINUTE(A2/38)/2 56)&"/"&A2,7)-34 This is an adaptation of the winning contest formula, =FLOOR(DAY(MINUTE(J/38)/2 56)&"/5/"&J,7)-34 that is presented on the Chip Pearson website.
It is Oudin's work that is now used extensively to determine the dates of Easter, even by the U. The restriction on the USNO algorithm is that it is intended to be used for years after 1899.The Astronomical Society of South Australia (ASSU), has quite an extensive section dealing with Easter and how to determine its date.The code is provided later, after the code for the UDF based on the USNO published algorithm.I've also contacted the ASSU and provided them with the code for the UDF to use at their discretion. However, as you'll see shortly, the version presented by Daniel.However, they fail immediately in 2079, then return accurate results through 2203, and then begin to become erratic as with the previous two formulas.
So in the final analysis, the worksheet formulas cannot be used reliably to determine dates of Easter after 2203, with two failures occurring as early as 2079 The most authoritative sources for algorithms suitable to be used as an Excel User Defined Function (UDF) would appear to be the work done by J. Oudin who tackled the inaccuracies in the formulas original derived by C F Gauß. This algorithm has been turned into an Excel UDF more than once - and was the one I elected to implement as an Excel UDF.Some islands with a partly Catholic population and many hotels will be offering specials on both dates, so be sure it's the one you want at the time of your visit.Go by the actual dates rather than saying something like "I'll be there Easter weekend!Before moving on to the other solutions, let us look at the apparent limitations of the various worksheet function solutions.It may very well be that these worksheet functions meet your needs and you don't need to look further.Additional algorithms have been attributed to Claus Tondering (page 26 and page 27) and Laurent Longre, who also publishes the More add-in for Excel. M in the groups.link above is a significant piece of code.