### A Fixed Date for Easter?

Every now and then in the past, proposals have been advanced to simplify the calculation of Easter. Already in 1539 the German church reformer Martin Luther argued in his Von den Concilijs vnd Kirchen that Easter should be celebrated on a fixed day in the calendar like Christmas.

In 1926 the League of Nations advanced a proposal to observe Easter Sunday on the Sunday after the second Saturday of April. Two years later the parliament of the United Kingdom passed the “Easter Act, 1928” [18 & 19 Geo. 5, ch. 35] that would enable the observance of Easter in the United Kingdom according to the proposal of the League of Nations at a future date as soon as a general agreement had been reached on this topic by all Christian churches.

So far, no such agreement has been achieved and the act has therefore not been brought into force. In 1999 the Earl of Dartmouth introduced a bill (“Easter Act 1928 (Commencement) Act 1999”) in the House of Lords to bring the act into force, but it was withdrawn on 11 March of the same year.

In mathematical notation, Easter Sunday according to the 1926 Proposal of the League of Nations would be equivalent with the first Sunday after 8 April and can be derived from the following algorithm:

Easter Sunday falls on 15 – mod(floor(5*y/4) – floor(y/100) + floor(y/400) + 6,7) April

with y denoting the year in the Gregorian calendar.

The following JavaScript calculator is based on the above algorithm and also gives the offset from the Gregorian Easter Sunday date.

 Year (Anno Domini) Easter Sunday April Offset from Gregorian Easter Sunday days © R.H. van Gent (2002)

As can easily be inferred from the above algorithm, the proposed dates for Easter Sunday can only fall between 9 and 15 April (inclusive) and repeat in a 400-year cycle.

Coincidences with Gregorian Easter Sunday are fairly common and during the 21st century these occur in 2001 (15 April), 2004 (11 April), 2009 (12 April), 2020 (12 April), 2023 (9 April), 2031 (13 April), 2034 (9 April), 2036 (13 April), 2039 (10 April), 2045 (9 April), 2047 (14 April), 2050 (10 April), 2058 (14 April), 2061 (10 April), 2063 (15 April), 2066 (11 April), 2069 (14 April), 2072 (10 April), 2074 (15 April), 2077 (11 April), 2085 (15 April), 2088 (11 April), 2093 (12 April), 2096 (15 April) and 2099 (12 April).

The proposed date for Easter Sunday will usually fall two weeks after the begin of Daylight Saving Time (Summer Time) according to the current rules in the European Union. However, when New Year’s Day in a common year falls on a Monday (as in 2001, 2007, 2018, etc., when the Dominical Letter is G) or in a leap year on a Sunday (as in 2012, 2040, etc.; when the Dominical Letter is AG), the proposed date for Easter Sunday (15 April) will fall three weeks after the begin of Daylight Saving Time (25 March).