I'm similar with confirmation but I work mostly with advance bookings, this suits my location, volume, lifestyle and clients.
Also I've had just as many same day mess around.
Even after paying deposits some forget, or disappear. My confirmation time is early and I don't accept day or evening before (some have vanished overnight).
Recently had 2 new clients tell me they want me to be comfortable, feel at ease, enjoy it then ask to confirm at a different time, can they bend the rules?
No and I need this confirm every booking because I've had no shows from second, third bookings as well as sudden deaths. My regulars seem to like this, it's part of their build up/rapport.