Changing my hours... How much notice to give?

Hi everyone!
I opened my daycare in January 2013 and I am happy to say that it is going well well except one thing... My hours.
Initially I was operating 7am-5:30pm. I have some parents who drop off at 6:45/6:50 which so that they can make the 7:13 Go Train and they pick up 3:30-4:30 latest so that is fine with me.
Currently I have 3 full timers in my care who after their initial issues with transition are doing great! I also have a few families who are part timers/on callers and I have a Wed child who I have posted previously about. This Wed child is on a completely different schedule than what I have here and has been here since March and still screams for Mama the entire time and refuses to play with the others. His hours are 9:45-6. He is the LAST one here for a good hour and its really beginning to take its toll on me as I am going since 6:45.
I am going to give the parents notice that my hours are changing to 5pm close effective July 1. Is that enough notice? I realize that its quite possible that they decide to find alternate care but for 1 day a week it simply not worth the aggravation anymore.
Thanks in advance!

That's plenty of notice...yup, do it. For 1 day, you're right, it's just not worth it. I work 6-6 so I get your sense of aggravation.

That's way too long of a day for you. I think that's more than enough notice.

Omigosh! I wouldn't do it. Give them notice and they can either get a grandparent to pick up the child earlier or find other care. You're not terminating them, you are giving them an option based on your business decision.

Plenty of notice. It gives them plenty of time to seek alternate care if the new hours don't work for them.

I'm going to send dcm an email later this afternoon.