On Sundays I do the school prep for the week ahead. Usually before that the only thing “school-wise” on the calendar are field trips or special workshops. I wait and go through the weekly lesson the Sunday before for both the OM week and the math unit. As of now this works out well since I do not have to “teach myself” any of the topics. I know my prep time with grow when more children are schooling and harder subjects are taught.
For a little more detail: