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 Amazon Web Services Region, occurring on a random day of the week.
Valid days: Mon, Tue, Wed, Thu, Fri, Sat, Sun
Constraints: Minimum 30-minute window.