help plz! phone won't keep time

I have samsung model sph-a660 phone.Whenever i open up my phone the time is allways wrong. This just started all of a sudden. The only way i can see the right time is to hit "menu" then "end" to bring it back to the screensaver, Which then displayes the actual time. Now lets say i close my phone at 3:30 , i wait 30 minutes and open it back up , my time is still displayed as 3:30. It stays there until i hit menu and end , which will then bring my time back to 4:00.
Also after i bring up the actual time the clock will still not change minutes.
this all happens on my spint coverage area and on a full charge.my phone is 9 months old.
Anyone that could please help , Thanks in advance!!!

Might be something wrong with the phone, go into and and set it to auto time

I can't find the time settings anywhere on my phone.Theres nothing in my user manual on time settings either . I e-mailed sprint about my problem and never got a reply.