The first week of school is usually the time for school principals to schedule individual teacher planning meetings. I am busy "roving" this week and next. Four days total at two different schools covering meetings for 8-9 teachers per day for 30mins each.
Since the teachers do not know who will be covering for their meeting time, the usual "plan" is pretty much monitoring the class while the kids continue work on their current assignment, outside P.E, silent reading or some other individual class work.
When roving, I take only a hat, whistle, pen, pencil, and my Kindle. The heavy subbing bag stays in the car.
The meetings themselves rarely last the full 30mins and that sometimes allows me time for the short restroom break or time to read the next couple chapters of my current Kindle book.
A usual single class subbing assignment starts 30mins before the school bell and ends after the end of day report is complete and the kids are gone.
A roving day starts about 15mins after school bell and ends after the last meeting is complete which can be as much as 10-15mins early.
That extra bit of sleep in the morning and avoiding the parent traffic jam in the parking lot in the afternoon makes "roving" an AOK day.