Description of problem:
Default time format on gdm login screen is wrong. My current
time is 23:11, but on gdm login screen it's 11:11 without any am/pm.
Most European locales (including my Russian) use 24-hours time format.
Version-Release number of selected component (if applicable):
Turns out the translation was broken. You just change
"%a %b %d, %I:%M %p" to
"%a %b %d, %H:%M" in the translation to get the 24 hour equivalent.
I just checked the Ukrainian translation in GNOME CVS and it is indeed broken
just like the norwegian one was. I've fixed it upstream for my translation, but
I can't fix the other ones myself.