Yes, it's important that you sync with the internets otherwise all sorts of posting chaos could ensue. Very quickly you will need a...
a... a computer
b... a watch
c... a interntet
If you use Linux, BSD Unix or Apple's OSX you can sync by clicking on the 'sync with the interntets' option when you adjust the date and time, otherwise you'll have to do it the old fashioned way.
Make a random post anyware on the forum. Your post will be stamped with official internet time in little letters at the top. Your PC wants to be accurate within +-32 seconds (a computer minute is devided into 64 as it's based on power of 2s), which could be tricky seeing as there will be a delay between posting, when the post appears, how long it'll take you to set the clock (control panel > date & Time) etc etc etc. This is where the watch makes things a bit easy.
It might be worth explaining that the forum works using a 64 second period to organise posts, user requests and whatnot which is why you can't perform multiple searches or make posts in quick succession.
You can check for success by making another spurious post anyware on the forum and comparing the time stamp with the system clock.
Jay