I believe one of the reasons for the Monday morning/Friday night imbalance, which any sensible person would agree is totally absurd, is the box-ticking Cut Down Overtime directive.
Thus, after the weekend, you can have a full complement on the morning shifts, fresh from their break (if any), but on a Friday night, the only way to have enough coppers is by paying them overtime to come in on their off-time.
Babys and Bathwater spring to mind so often when it comes to hearing similar tales of how the bureaucracy (across ALL aspects of government) works, or rather doesn't.
And the police, like the health service and other 'necessary' workers in the social sector, are stuck in the middle of this nonsense, most wanting to do their job, and most constantly blocked by the incompetence of their masters.
A.