You can set your computer time and date to whatever you wish. It was probably set at the store or by the installer, or your ISP might be supplying it automatically. I use a product called "Atomic Clock" -- you can ping various atomic clocks around the world and your PC will be automatically set to the correct time for your time zone.

Or go to tycho.usno.navy.mil -- the official US time service, operated by the US Naval Observatory. (No www's there.)