Amazon MQ now supports updating the maintenance window time

You can now update the maintenance window start time for your Amazon MQ brokers. Every Amazon MQ broker has a weekly 2 hour maintenance window during which changes are applied. These changes can include broker version updates, configuration changes, or patching of the operating system and other system software. The maintenance window gives you control over when these changes occur, in the event either are requested or required. You can minimize downtime during maintenance by using Multi-AZ brokers. The maintenance window start time can be changed using the console, CLI, or API.

Source:: Amazon AWS