Is May 21st 2011 real or false?

Alright so I keep here about the world ending saturday cause some preacher calculated something but I thought in the bible noone is suppose to know when so now Im really scared I been so sick to my stomach I had a panic attack when I seen the AD I even tried talking to my grandpa which is an ordained minister and he was saying that he believes this man is a false prophet and if he knew anything about the bible then he should no your not suppose to predict it. It seems like Im still worrying too much I like to have some advice on what you think?