You might look at this thread: Saving Sequential Back Ups During Development
But insted of an Install OnTime script, you could use OnLastWindow close (Of the filemaker 11 equivalent) in File Options to do this:
If [ Get ( AccountName ) = "Fred" ]--> put the desired account name in place of "Fred".
Save a copy as
The two steps inside the IF will be ones used in the other thread (But use ".fmp12" instead of ".FP7" if you are using FileMaker 12.