Again, let's try to understand this in an econ 101 sense. The change is not in the period of the rental but in the amount paid for the rental. If revenue decreases, less money will be available to pay for everything and (whether proportionally or not), prices will go down. If you work 8 hours a day, 5 days a week, and you are reduced to 4 days a week, you will not feed your family fewer days a week, but you will feed them brisket instead of filet mignon. And if everyone does this, the price of filet will fall.
Re alternates, this is of course an issue that will not alter the schedule of the rank and file worker but only of the especially burdened (and usually already higher paid) performers.