How much does it cost to keep the facility open for 1 minute? Power, staff, etc. And then there's the challenge of keeping people on staff at all when parents

How much does it cost to keep the facility open for 1 minute? Power, staff, etc. And then there's the challenge of keeping people on staff at all when parents consistently make the staff work late. Beyond that, it seems like a good way to achieve the objective of convincing parents to not offload externalities onto others by being late.