title: What is the format for --date parameter of git commit
body: <p>I need to overwrite the date of the commit of Git, all the documentation points to <code>--date</code> parameter, but then leaves one without a clue to the appropriate format. I've tried every permutation I can think of, and i'm getting:</p>
  <blockquote>
  <p>&quot;fatal: invalid date format:&quot;</p>
  </blockquote>
  <p>error for each and every one.</p>