public void setPreferredBackupWindow(String preferredBackupWindow) {
        this.preferredBackupWindow = 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 Region. To see
the time blocks available, see <a href=
"https://docs.aws.amazon.com/neptune/latest/userguide/manage-console-maintaining.html#manage-console-maintaining-window"
>Neptune Maintenance Window</a> in the <i>Amazon Neptune 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>

@param preferredBackupWindow
       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 Region.
       To see the time blocks available, see <a href=
       "https://docs.aws.amazon.com/neptune/latest/userguide/manage-console-maintaining.html#manage-console-maintaining-window"
       >Neptune Maintenance Window</a> in the <i>Amazon Neptune 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-neptune/src/main/java/com/amazonaws/services/neptune/model/CreateDBClusterRequest.java