In addition to {TAIL ~ the master calendar}, a user may add {HEAD ~ secondary calendars} in the present invention 
In addition to { TAIL ~ the master calendar } , a user may add { HEAD ~ secondary calendars } in the present invention
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH