Amazon RDS on Outposts pricing

On-Demand DB Instances Management price let you pay for managing by each hour when your DB instance runs, with no long-term commitments.

RDS on Outposts pricing is based on a per-instance hour management fee for each database managed. Partial DB instance-hours are billed in one-hour increments following a billable status change such as creating, starting, or modifying the DB instance class. For example, when you run a DB instance for 30 minutes and then terminate the instance, you are billed for one DB instance-hour.