We always open Monday 9-6, not full staff, just myself, another stylist and Junior, and I am always busy and other stylist about 75% - I find most of my Monday clients like it cos its quieter than the rest of week when full staff in or come in cos it's their day off.
We have always opened Monday and once people know they will come in.
I think part of opening Monday is making sure people know, some still assume all salons close on Mondays. x