Can a new reservation start the exact moment the previous one ends?

Yes — there's a setting for this called Back-to-back reservations. By default, BRM treats two bookings on the same item as conflicting if one starts at exactly the moment the other ends, so staff (and online customers) see the item as unavailable for that instant and have to leave at least a small gap. Turning this setting on removes that restriction: a new reservation can start the exact second the previous one's rental period ends.

Where to turn it on

Settings > Administration > Features > Back-to-back reservations. It's off by default, and any store admin can switch it on themselves.

Rental buffers still win

If the item or product line involved also has a rental buffer configured — the gap BRM automatically adds between bookings, e.g. for cleaning or maintenance — that buffer takes precedence regardless of this setting. A 30-minute buffer, for example, still keeps a 30-minute gap even with Back-to-back reservations switched on. The toggle only removes the default zero-tolerance rule; it doesn't override a buffer you've deliberately configured.

See Also: Adding buffer time between bookings