Having just left a coach operator where I was a scheduler I thought I’d chime in!
Luckily 75% of our operation was scheduled services whether that be schools or works contracts that we had. Majority of our drivers were full time (we guaranteed 45 hours) and some schools were covered by part timers who worked a variety of hours but mostly AM/PM schools though we had a few who did 2 or 3 days a week or casuals who would particularly help out on weekends (which was handy!).
In terms of days of the week - the vast majority of our work was Mon-Fri (schools) but our works contract ran to the same schedule 7 days so often weekend (split) shifts on these were overtime.
We generally worked on full time drivers working 6 days one week and 5 days the next, but when it was quiet we’d give some drivers days off during the week, usually a Monday or Tuesday! Casual drivers helped us out by covering weekend shifts so there was less for full timers to cover. That just meant we could take on extra private hires or rail replacement on a weekend. Equally we had office staff like myself who could cover school contracts to allow drivers a day off so that we could work them over the weekend.
The general pattern though was Mon-Fri & one of Sat/Sun, then the next week Mon-Fri with a ‘45’ that weekend. We’d generally try to have half of them on opposite weekends.