public String getPreferredBackupWindow() {
        return this.preferredBackupWindow;
    }
<p>
The daily time range during which automated backups are created if automated backups are enabled, using the
<code>BackupRetentionPeriod</code> parameter.
</p>
<p>
The default is a 30-minute window selected at random from an 8-hour block of time for each Amazon Web Services
Region. To see the time blocks available, see <a
href="https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/AdjustingTheMaintenanceWindow.html"> Adjusting the
Preferred Maintenance Window</a> in the <i>Amazon RDS User Guide.</i>
</p>
<p>
Constraints:
</p>
<ul>
<li>
<p>
Must be in the format <code>hh24:mi-hh24:mi</code>.
</p>
</li>
<li>
<p>
Must be in Universal Coordinated Time (UTC).
</p>
</li>
<li>
<p>
Must not conflict with the preferred maintenance window.
</p>
</li>
<li>
<p>
Must be at least 30 minutes.
</p>
</li>
</ul>

@return The daily time range during which automated backups are created if automated backups are enabled, using
        the <code>BackupRetentionPeriod</code> parameter.</p>
        <p>
        The default is a 30-minute window selected at random from an 8-hour block of time for each Amazon Web
        Services Region. To see the time blocks available, see <a
        href="https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/AdjustingTheMaintenanceWindow.html">
        Adjusting the Preferred Maintenance Window</a> in the <i>Amazon RDS User Guide.</i>
        </p>
        <p>
        Constraints:
        </p>
        <ul>
        <li>
        <p>
        Must be in the format <code>hh24:mi-hh24:mi</code>.
        </p>
        </li>
        <li>
        <p>
        Must be in Universal Coordinated Time (UTC).
        </p>
        </li>
        <li>
        <p>
        Must not conflict with the preferred maintenance window.
        </p>
        </li>
        <li>
        <p>
        Must be at least 30 minutes.
        </p>
        </li>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/model/PromoteReadReplicaRequest.java