Why the timetable is the easy part
Every scheduling tool can draw a grid of weekly slots, which is why demos are uninformative. The grid is never the problem. The problem is that a real teaching week is mostly exceptions: the Tuesday student who moved to Thursday, the lesson cancelled at twenty minutes' notice, the make-up promised in March that nobody recorded, the term break someone forgot to delete from the calendar.
Generic calendars and booking apps store events, so every exception is handled outside the system — in a notebook, a spreadsheet, or your head. That works at ten students and collapses at forty, because exception-handling work grows faster than the roster does.
Lesson scheduling software earns its place by carrying the concepts a calendar lacks: what a student is, what a term is, what a cancellation policy is, and what happens to the money when a lesson does not happen. Once those exist in the system, an exception is recorded at the moment it occurs rather than reconstructed at the end of the month.

