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): 2.4.1.3-1
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.