How do you solve a staffing problem by reducing the number of hours your current staff works?
If you don't have enough staff to cover the shifts, you cut services. My wife works as a police/fire/EMS dispatcher. They don't get to cut service hours, so each dispatcher was assigned 42 hours a week when one left after a pregnancy problem. When the 3 women who were all pregnant at the same time left for 90 days maternity leave, the remaining dispatchers worked 48 hours per week each to cover 7/24. Only 2 returned, so the supervisor is filling in while the rest of the staff works 4 x 10 shifts. The city has had no success replacing the dispatcher who didn't return from the 90 day maternity leave AND my wife plans to retire at the end of this year. It takes 15 weeks to train a replacement once you have a hire that can complete the training and perform the job.
The more simple answer to your question is cutting back to 32 hour weeks means people come to work M->Th and not on Friday. Less service provided to the taxpayer in this instance, but fewer shifts to staff. Honestly, they should get paid for 32 hours of labor not 40.