FreeBSD source tree https://cgit-dev.freebsd.org/src/atom?h=release%2F14.4.0 2024-12-16T10:37:08Z 2024-12-16T10:37:08Z Dag-Erling Smørgrav des@FreeBSD.org 2024-12-09T12:37:45Z urn:sha1:259dcedc4ade538c35100d364e5cfe30b89c9a95 The day-of-week calculation used the raw year value without adjusting for TM_YEAR_BASE, so it was off by one for 300 years out of every 400; it just happened to be correct for 1901 through 2000. It also used a loop where a simple addition would have sufficed. While here, simplify our version of Gauss's algorithm, and document that we assume the Gregorian calendar. MFC after: 1 week PR: 282916 Reviewed by: imp, allanjude, philip Differential Revision: https://reviews.freebsd.org/D47977 (cherry picked from commit 4285e024baa80f81d13cdcc016fdf0721fe57862)