I've set up a calendar for a meeting room we have in the office and set list permissions to prevent users from deleting another person's booking. The last step is to prevent people from being able to create a booking at the same time as another booking.
I thought this would be a simple validation rule - especially since there is a "check double booking column" but I can't for the life of my figure this out.
All the solutions I can find are around the "resource calendar" feature in SharePoint 2010, which no longer exists in 2013.
Does anyone have any idea how to set up this functionality in 2013?