fix: correct %V ISO week at leap year boundaries#133
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fix: correct %V ISO week at leap year boundaries#133Koan-Bot wants to merge 1 commit intocpan-authors:mainfrom
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When a date falls in early January and its ISO Thursday belongs to the previous year, format_V adjusts $thu by adding the previous year's day count. If that previous year is a leap year (366 days), the adjusted $thu equals the current year's $ylen (365), incorrectly triggering the year-end check and returning week 01 instead of the correct week 53. Fix: only apply the year-end check ($thu >= $ylen) when Thursday was NOT already adjusted to the previous year. The year-end check is meant for late-December dates whose Thursday falls in the next year, not for early-January dates already handled by the previous-year adjustment. Affected dates: Jan 1-3 of any year where: - January 1 is Thursday, Friday, Saturday, or Sunday, AND - the previous year is a leap year Example: 2021-01-01 (Fri) returned %V=01 instead of %V=53. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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What
Fixes
%V(ISO 8601 week number) returning01instead of the correct week number for early-January dates when the previous year is a leap year.Why
When a date like 2021-01-01 (Friday) belongs to ISO week 53 of 2020,
format_Vcorrectly identifies that Thursday falls in the previous year and adjusts by adding 2020's 366 days. But the adjusted value (365) then matches the current year's day count (365), incorrectly triggering the year-end check and returning week 01.The year-end check (
$thu >= $ylen) is meant for late-December dates whose Thursday is in the next year — it should never apply when Thursday was already adjusted to the previous year.How
Move the year-end boundary check into an
elsebranch so it only applies when no previous-year adjustment was made. The$thu < 0path (previous year) and$thu >= $ylenpath (next year) are mutually exclusive by definition.Testing
strftime("%V")for 14 year-boundary dates — all match🤖 Generated with Claude Code