Maintenance sessions are every Sunday from 12 till 2 because historically no one wants to rehearse during this time. These two hours allow the Theatre and Tech Managers to carry out any maintenance or repairs they have to do. The FoH manager should also use this time for general tidying emptying bins etc.
Many hands make light work but it is difficult to persuade people to get up for this time on a Sunday, bribing people with breakfast occasionally happens.
There is a list of stuff which really should be done on the Building Improvements page