I recently had to do the same thing. Change my closing hours. I had my hours 7-5:30 but all families except 1 were picked up by 4:45. I had 1 family whos parents would arrive at pickup in their casual clothes, so it was clear they were going home first and running errands before picking up their child and I was waiting an extra 45 minutes for THEM. I posted a notice and handed it out to all parents saying that I was closing now at 5:00 and there would be $1 minute late fees.