I had thought there was a limit of something like two weeks prior to the election. If the ballots for the June 9 election were sent out on May 10th, your rule of thumb would mean most people could return them starting around the 18th of May. That’s three weeks before the election.
That’s not just a matter of a few days after the May 6th, endorsement, but it’s not as long a time frame as I had thought it to be either. I would have guessed the absentee ballots could be legally sent off around the 25th of May.
People receiving their ballots on May 12 (6 days after the endorsement) could vote and return the ballot on that day, we are not required to store them somewhere in the house until a certain date.