Talk:Doomsday rule: Difference between revisions
Not a robot (talk | contribs) (I think the leap year calculation in the only example has a bug) |
(ISO 8601 / sunday is 7) |
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--[[User:Not a robot|Not a robot]] ([[User talk:Not a robot|talk]]) 11:40, 1 June 2021 (UTC) |
--[[User:Not a robot|Not a robot]] ([[User talk:Not a robot|talk]]) 11:40, 1 June 2021 (UTC) |
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== Sunday is 7 not 0 == |
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At least accordin to ISO 8601, not that programmers would forego a zero-based index just to conform to a petty standard... :-) --[[User:Petelomax|Pete Lomax]] ([[User talk:Petelomax|talk]]) 18:17, 1 June 2021 (UTC) |
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Revision as of 18:17, 1 June 2021
January 6, 1800
The Julia example (supplied by the task writer) claims January 6, 1800 was a Sunday. However, I am pretty sure it was a Monday (that's what I get when I try to implement it, and both Linux cal and WolframAlpha also agree with me).
I think the leap year determination is wrong in the Julia example. It says:
<lang julia>(year % 4 != 0) || (r == 0 && year % 400 == 0) ? # leap year determination</lang>
where r is the year modulo 100.
I don't know Julia but it seems that this checks whether the year is divisible by 4, and if not, by both 100 and 400. It should be (divisible by 4 and ((not divisible by 100) or divisible by 400)). Surely this should instead be: <lang julia>(year % 4 != 0) || (r == 0 && year % 400 != 0)</lang>
--Not a robot (talk) 11:40, 1 June 2021 (UTC)
Sunday is 7 not 0
At least accordin to ISO 8601, not that programmers would forego a zero-based index just to conform to a petty standard... :-) --Pete Lomax (talk) 18:17, 1 June 2021 (UTC)