GigSpace chases your acts so you don't have to. Each booked act is asked to re-confirm in the week before the gig, and again on the morning of it.
If an act doesn't confirm, you're told. If they still don't, GigSpace can cancel the booking and offer the gig to your backups automatically.
The day-of alert, a gig today with nobody confirmed, is the one notification that can't be muted. It's the last line before a venue is left short.
You can see the confirmation state on every upcoming gig, so the Friday-morning question of "who's actually turning up tonight" has an answer on one screen.