I have an iphone 4 and yesterday I briefly changed to 24 hr time and then turned it back off. My lock screen is stuck in 24 hour time. I've gone back and made sure the 24 hour time was turned off. I checked international settings and did a restart holding down the home and sleep buttons. That didn't fix the problem.
iPhone 4, iOS 5.1.1
reset all settings by going to settings> general> reset all settings
I'm sure at this point you've figured it out but it just happened to me as well with the new update and the following helped me after I tried raymiemusser's advice without success:
Bizarrely - if you set your region to New Zealand ... Go on , try it lol!
Settings - general - international - Region Format
Then go back and change back to United States and you're back in order!!
Your suggestion absolutely worked! It sounded strange, and maybe like it was a joke. But it did indeed fix the problem of time stuck in 24 hour mode in the lock screen. Thank you!
iPhone 4 stuck in 24hr time
