App Limits only active during certain times of the day

I have no social media or games on my phone so I mostly get distracted with messages during the school day. But out of school hours, messages is really helpful and I don’t want a limit on it. So it would be nice if I could only enable a certain app limit in certain hours (yes I know you can set it to certain days). During school I spend so much time on messages so I would like to limit it to something like a 10 minute use before it’s blocked for 40 minutes during the hours 7:00-3:00 but want unlimited usage during the afternoon after school hours.\

Can you explain how you setup now? Is Schedule Session doesn’t work?