Using nl_langinfo in parse-datetime?

[Collin Funk]

Hi,

I'm curious if it would be a welcome change to use nl_langinfo in
parse-datetime.

This would make 'date' more friendly to users who do not speak English:

    $ LC_ALL=fa_IR.UTF-8 date +%a
     پنجشنبه
    $ LC_ALL=fa_IR.UTF-8 date -d 'پنجشنبه'
    date: invalid date ‘پنجشنبه’

We could avoid allocating the lookup tables if LC_TIME=C, or if an
English name is matched, for backwards compatibility.

WDYT?

Collin