every day or two mine will report the weather and time thinking I'm in some random city in arizona or california, and I'm on the east coast. Most times I ignore it and when the weather widget updates again it ususally corrects itself.
The time on the phone is network-determined. Is the issue still occurring? It could be a glitch on your local cell site. Do you have any other phones in the area with similar issues? What zip code are you in? I can check my trouble ticket system to see if anyone else in the area are reporting similar issues so we know where the problem is lying: Device or Network.
Let us know how we can further help, and feel free to PM me if we need to go over any account-specific information.