Why timing changes what is asked
A cleaner attending at six in the evening, after students and staff have left, presents a different situation from one working through the afternoon while classes run. Most schools set their contractor rules accordingly, with tighter requirements for anyone on site during school hours or during out-of-hours programs. That is why the first question in any school engagement is when the work occurs, not what it includes.
It also explains why arrangements need revisiting when the schedule changes. A contract that began as an after-hours service can drift into daytime attendance through periodic work, holiday programs or an added day porter. Each of those changes may move the engagement into a different category from the school's perspective, and the school would generally rather be asked than discover it.
