Val, this will be extremely embarrassing for you, and I will deserve an apology, but the document that you posted has nothing to do with Kerry's discharge from the service. The document is for Kerry's graduation from the US Naval Officer Candidate School dated 15 December 1966. Approximately six years later, on 17 February 1972, would be Kerry's Nominal Date of Expiration of Assignment. That is when it was anticipated he would get his honorable discharge from the Navy but of course, we know he was let out early with a less than honorable discharge.
Now for the bad news. Kerry's discharge document is on his site and it shows 1978. Plus it shows a reference to some regs as for the reason it was so late. So now I am going to have to do some more research and find out why his discharge was changed to honorable under President Carter's amnesty program for Vietnam era undesirables.