Amazon RDS maintenance is sometimes required to update a database engine version or the operating system (OS) of an instance or cluster. The duration of the maintenance varies based on the operations that are scheduled for your instances and which operations start during the maintenance window.

When you create or modify an instance, you can configure the maintenance window. You can schedule maintenance to occur once a week at a specified time and that lasts between 30 minutes and up to 12 hours. This sets the window during which maintenance actions from Amazon RDS can be scheduled and started.

Maintenance Window end time

Updates can take longer to complete than the maintenance window time frame. For example, updates can take longer if there is a large list of files that must be updated or if an instance restart is required.

When the instance is updated, the duration of the downtime varies based on whether the maintenance is an OS update or a database engine version update.

Note: The Amazon managed maintenance period can't be proactively started outside the maintenance window, but you can adjust your weekly maintenance period accordingly. If you want scheduled maintenance to occur sooner, you can Adjust the Preferred DB Instance Maintenance Window to occur according to your needs.