allow only 1 booking per day, hours

Hi, I have been tasked with making a website for our sauna association.
Where members can, among other things,
book the sauna, check the sauna's bookings
and participate in the sauna's events.
I have tested Jem and it works as I intended.

But would need help making a modification.
modification I need help with is the following:
When, for example, a member creates a sauna event: Friday, July 20 between 12:00 and 15:00, only 1 sauna event can be created during the same time.
If another member tries to create a sauna event, 10:00 and 15:00 , they will receive a message that the sauna trip is booked then.
But the member can book the sauna, , July 20 at 15:00 and 20:00
So I need a modification that means you cannot double book the sauna.
someone can help me fix this modification please

Regards
David

Hello, you can create an event (like Sauna) at a certain time, for booking, you must go to the extended tab and choose event registration=yes,
You can choose the max places etc. Save this
then the users can book this event at the end of event details!
It needs only 1 creating of event, the rest is booking this event, if the general JEM setting for eventregistration is set "yes" or "use event setting"
and in event extended tab event registration=yes.