phone sph-a660

Whenever i flip my phone open the time is allways wrong,sometimes it doesent even display the time.

The only way i can see the correct time is to hit menu then end , bringing me back to my screensaver which will display the right time.

For instance:If i close my phone at 3:00 and reopen it at 3:30 it still shows time as being 3:00 untill i press menu and end.
I
v'e looked through my user manual and can't find any time settings on my phone.
I also e-mailed sprint about my problem and never got a reply.
Thank you in advance for any help anyone can give me.