Finance knows the number on the first of the month

The rental is billed when it starts. The full period is debited from the General Balance, an invoice is generated, and that's the month's infrastructure number. It doesn't change on the 31st.

Nothing on the server is metered on top. Containers don't have a price. Snapshots, cron runs, daemons, exec calls don't have a price. Bandwidth and storage are in the tier. So there's no meter to read at month end, no usage line that came in above forecast, no cost-anomaly alert at 2am because a job ran twice.

The FinOps playbook: tag everything, reconcile the allocation report, argue about reserved capacity: was written for a substrate where the bill is computed after the fact. Here the bill was computed before the month started, by you, when you clicked Rent.