I can't think of one Mike, having said that I also can't think why it would be desirable to do so.
Generally you can't rely on listeners to connect exactly on time. You may wish to think of the problem a little laterally.
If I had content that was only available at a certain time I would use a streaming service that has some kind of "auto DJ" when I wasn't connected (the first "Google" I found on the subject is: https://www.stream101.com/knowledgebase/docs/stream-hosting/auto-dj/how-does-the-automatic-liveauto-dj-switching-feature-work/ )
My auto DJ would be an announcement saying "tune in at 8am for the next broadcast from <station name>" and some kind of royalty free music bed and just loop that for all non broadcast hours.
I'm afraid this function is not available but there is a feature request for it here: https://www.playitsoftware.com/Support/FeatureRequests/549/Scheduled-streaming
Is there a way to start/stop streams automatically. Our shows start at 8am and end at 10pm. I would like to set up hard and stops at those points