The start of the 2 hour maintenance window.
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.
If you set the read replica maintenance window to \"\", the read replica is set same as the DB system maintenance window. If not specific by the user, there will be no changes to the maintenace window.
The Maintenance Policy for the DB System or Read Replica that this model is included in.