bug#21229: 24.5; parse-time-string ignore PM/AM

[Nicolas Richard <youngfrog@members.fsf.org>]

Tino Calancha <f92capac@gmail.com> writes:
> Maybe  parsing "%c" looks too ambitius for the
> freedoom of the output format.

Also FWIW, parse-time-string won't parse (format-time-string "%c"
(current-time)) correctly in many non-english locales because it won't
recognize the month names.

In my french setup:
(format-time-string "%c" (current-time)) => "mar. 11 août 2015 07:34:35 CEST"

"mar" stands for "mardi" (= Tuesday), but will be understood as "March" :
(parse-time-string "mar. 11 août 2015 07:34:35 CEST") => (35 34 7 11 3 2015 nil nil nil)

> We may need something like:
>
> once you find "am" "pm" look the token: "HH:MM:SS" and ask:
>
> when "pm" and HH < 12: HH ---> HH + 12

Currently parse-time-string works with rules (they are found in
parse-time-rules), each setting one element of a (SEC MIN HOUR DAY MON
YEAR DOW DST TZ) list. When one such element is set, parse-time-string
won't modify it anymore. So we need a small change in the design here if
we want to take PM into account.

-- 
Nico