User talk:109.40.130.52

The example calculation for 1966's doomsday lacks taking the remainder after adding the anchor day. This gives an invalid result. See for yourself (where % is the modulo operator): floor(66 / 12) is 5, 66 % 12 is 6, and floor((66 % 12) / 4) is 1, so the sum of these is 12. Taken mod 7, this gives 5. Now if "Wednesday" (3) is added to that result, this gives 8, which is an invalid day number. The result becomes valid again if again taken mod 7 to become 1, which - at least in the anglo-saxon world - is the day number for Monday.

Alternatively, and not violating the algorithm AFAICT, the anchor day's number should be added first, and only then the remainder should be taken. This would give ((5 + 6 + 1) + 3) = 15 in the example given and, if taken mod 7 at that point, 1 which is the correct result.

Hth, - Thomas