bug#45608: 28.0.50; calendar-iso-date-string: "Day 6 of week 53 of 2020"

[Lars Ingebrigtsen]

Jean Louis <bugs@gnu.support> writes:

> (calendar-iso-date-string) gives following information on this day:
> "Day 6 of week 53 of 2020" which I consider wrong as it is 2021 and
> the year has 52 weeks normally, the days at begin of the new year
> should not be considered past year.

https://en.wikipedia.org/wiki/ISO_week_date

"An ISO week-numbering year (also called ISO year informally) has 52 or
53 full weeks. That is 364 or 371 days instead of the usual 365 or 366
days. The extra week is sometimes referred to as a leap week, although
ISO 8601 does not use this term. Weeks start with Monday. Each week's
year is the Gregorian year in which the Thursday falls. The first week
of the year, hence, always contains 4 January. ISO week year numbering
therefore slightly deviates from the Gregorian for some days close to 1
January."

Closing.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no