Overage Billing needs to process the previous month or run as a separate job
Overage billing runs as part of the regular cron job on the last day of the month, we run the cron at 8am every morning to generate invoices and collect payments.
The problem is that the overage billing at the end then misses out the remainder of the last day of the month. The only way to avoid this is change our cron to 23:59 but this isn't appropriate for our invoicing of clients.
A better system would run on the first of the month for the previous month's stats (I know cPanel no longer has them so maybe this isn't an option) or be able to be run separately at 23:59 on the last day of the month.