I work in a hairdressers but whether I am booked up or not I am there, I would hate to think of missing a walk in. You never know, they could end up becoming a repeat client, lots of mine have.
I may take a chance on a very odd occasion and leave an hour early if Ive had a very slow day but Im always there bright and early and would stay until late if someone wanted me too even if I was quiet until they came in.
HTH XX