preferredMaintenanceWindow

The weekly time range during which system maintenance can occur, in Universal Coordinated Time (UTC). Format: `ddd:hh24:mi-ddd:hh24:mi` The default is a 30-minute window selected at random from an 8-hour block of time for each AWS Region, occurring on a random day of the week. To see the time blocks available, see Maintaining a DB instance in the Amazon RDS User Guide. This property applies when AWS CloudFormation initially creates the DB instance. If you use AWS CloudFormation to update the DB instance, those updates are applied immediately. Constraints: Minimum 30-minute window.