Is GitHub adequate for purposes of giving a manuscript a timestamp to protect against plagiarism? I wrote a paper that I want to put on my webpage, but that I don't want to publish anywhere.  I think that I need a timestamp on it, in case someone decides to plagiarize it.  Is GitHub adequate for this?
Let's be scientists (It was fun to try out):
below is a small repository, where I first tried 'lol' to have a timestamp in the future ... doesn't work; but at least in 'history' I could backdate (bit unlikely that I authored s.th. in git 1980 ;-).

But at least the day that I pushed is set by github.com. In total, though, I wouldn't trust this scheme. ``I forgot to push but look at the authored date, I totally solved it years ago''.

Jul 15, 2014

history
2b5d4208aa Browse code 
choener authored on Jan 1, 1980

lol
fc2a68a571 Browse code 
choener authored just now

https://github.com/choener/lol/commits/master