How many minutes will/can a 15 year old work in Ohio?

I was thinking of getting a job at KFC since it said, “now hiring 15 year olds.” I looked things up and it said, “when school is not in session... a 15 year old can work up to 40 hours a week”, but I don’t expect to work 49 hours a week for my first job. I also know it’s depending on the manager or who ever controls this. (Can I also be told how much I can work in a 7 day week when school is on?) Thanks! :)