how to set internal date and time??

Ok, so this is probably a lame question, but i am new at this. for some reason, all the email i send out (using Entourage) is time stamped an hour off. Any email I receive is also an hour off. However, my computer's clock (that I can set through system preferences) is correct and when I set tasks to pop up through Entourage, they always pop up at the correct time. I am not sure what is going on here. I was told that I need to change the computer's internal clock and have no clue how to do that. Please help

Thanks!

This maybe a stretch (someone correct if I'm wrong) but I believe zapping the PRAM purges the primary RAM for running things like the internal clock. It never hurts to try. Reboot your computer and hold down Command (Apple key) + Option + 'P' + 'R' keys until you hear three chimes go by, then release. Let it finish booting and see if your problem persists. Check the clock and let us know if it works.