Booking conflict rule
The booking conflict rule is the server-side rule that prevents two confirmed bookings from overlapping on the same asset. It rejects the later of any two confirmed bookings whose time ranges overlap.
The check happens on the server, not just in the app. It holds regardless of which device the two bookings were created on, and it holds when one booking was created offline and the other was booked online in the meantime. The later write to reach the server is rejected and surfaces as a sync error on the losing device.
The server’s rule applies only to confirmed bookings, and it is checked again at the moment a booking becomes confirmed. The app asks before saving: a tentative booking is refused only by a confirmed one, so tentatives can overlap each other and pending or suspended bookings; any other booking is also refused by a pending or suspended one.