ICal has gone missing? Any ideas?

So, i’m generally very good with computers, but this is a new one for me. Last Friday I left for the weekend, left my laptop at home, everything was fine. Today I tried to open iCal only to find that it is gone. Completely missing. Not in the applications folder, doesn’t get picked up by spotlight, or a search of the hard drive. Any idea where it could have gone and how to get it back?