To check when you start/boot up your PC it shows a date in the first screen.
it will/may give the M/baord make if not the BIOS string number which is a mix of numbers/letter and long.
somewhere will be ??/??/?? in this screen.
Best way to do it, is to get your finger on the Pause break key on keyboard and pause the screen, press enter to go to next but you have to be quick.
Also if you press del key continous, when starting pc up you will enter the bios, the top of the bios screen will/may also tell you the date.