The start of the maintenance window in UTC.
This string is of the format: \"{day-of-week} {time-of-day}\". \"{day-of-week}\" is a case-insensitive string like \"mon\", \"tue\", &c. \"{time-of-day}\" is the \"Time\" portion of an RFC3339-formatted timestamp. Any second or sub-second time data will be truncated to zero.
PostgreSQL database system management policy update details.