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