[PATCH] en_US: define date_fmt (bug 24046)

[Florian Weimer]

* Aurelien Jarno:

> The en_US locale use a 12h am/pm format in both d_fmt and d_t_fmt, which
> is correct, but does not define date_fmt. This cause the default value
> to be used, which is in 24h format.

Perhaps this format was chosen for alignment with asctime?
Is there any system which uses 12h format with the date command?

I wonder whether our users expect such a change.