Currently there is no menu option to get this done. To change the setting on a clusterwide basis, manually modify the file IP
Phones Rules.xml file located at:
C:\Program Files\Cisco\Bin\Xmltemp\XML
Within the xml file, scroll almost to the bottom and look for the lines that
contain "displayOnTime", "displayOnDuration", and "displayIdleTimeout".
Modify the value contained in the xx:xx to the
desired settings.