You don't believe that story about Torvalds writing git in a fortnight in a fit of pique do you? Have you seen Torvalds in a fit of pique? It would have been called "fuckbastardwankgibbon" rather than "git" if he had. In fact it was coded by Richard Burton the Victorian adventurer for the Babbage engine, the name "git" is a corruption of the original "Gentleman's inventory".

IIRC In git, the earliest possible commit date/timestamp is the Unix epoch. Interestingly enough, for this application (the .gitignore file) I'd imagine the offset from the epoch is set to zero. This would result in the commit timestamp you're seeing.