preferred hour/minute offset is not supported by all ANSI C libraries. Also, a
strict reading of the original 1982 :rfc:`822` standard calls for a two-digit
year (%y rather than %Y), but practice moved to 4-digit years long before the
- year 2000. The 4-digit year has been mandated by :rfc:`2822`, which obsoletes
- :rfc:`822`.
+ year 2000. After that, :rfc:`822` became obsolete and the 4-digit year has
+ been first recommended by :rfc:`1123` and then mandated by :rfc:`2822`.