Re: BUG #1217: wrong date->number of week conversion - Mailing list pgsql-bugs

"PostgreSQL Bugs List" <pgsql-bugs@postgresql.org> writes:
> Frankly speaking I don`t know the adequate calendar ISO norm  in detail, but
> the last days of year shouldn`t be counted as F_I_R_S_T week of that year. I
> expected PostgreSQL rather to return 2003-53-29.

You are mistaken.

The ISO week is defined as Mon-Sun where week 1 of a year is the week
containing the year's first Thursday.  Don't ask me *why* it's defined
that way, but it is.  2004's first Thursday is Jan 1, so that week
extends from 2003-12-29 to 2004-01-04.

            regards, tom lane