Can I limit how long my child can use the iPad in one sitting instead of the whole day.

I want to limit how long my child can use his iPad at one time, specifically so that he can only use it at one hour intervals. So, of he is watching YouTube, the iPad would turn off at the 1 hour mark. If I allow 3 hours of screen time on a Saturday, I don't want him to use all 3 hours at one time, but I don't care about what time of day he uses them. So far, I understand how to set the limit for the entire day or schedule specific times during the day, but there doesn't seem to be a to limit how long he can stay on at one time while being able to use the iPad multiple times a day. Is there a way to achieve this with the existing parental controls, or would a third party app be necessary?