CFS 1 Yes, undo

He smiles as you tell him you want to change things. His holographic head flickers and he says, "Put on this digital calculator watch, what ever you do don't remove it. When you are ready type 5318008 and time will restart 24 hours ago, but you can only do this once, doing it again will just erase you from history, just as you are about to wipe out your previous self now. If-" an man from the darkness behind him taps him on the shoulder, he is dressed in a strange futuristic faceless mask.

"Ok we have to go now," says the hologram headed 80's businessman, "Just don't break those three rules!" and he and the two identical futuristic soldiers behind him all press their watches and vanish into neon patterns before you can say anything.

What do you do?

 * Type 5318008 into your calculator watch
 * Decided not to do it after all