Bought my phone a couple weeks ago but the last few days I've been having problems with it randomly rebooting out of the blue, and it not keeping the correct time.

Not sure what to do about the first issue, but the time issues i've already tried both the automatic time setting and manually setting, but the problem remains. Also tried asking for help on the samsung facebook help page but their suggestion of just clearing the clock cache didn't seem to do anything. Any suggestions?