Plan to drop Christmas broadcast (8)
I believe the answer is:
schedule
'plan' is the definition.
(schedule is a kind of plan)
I cannot understand how the remainder of the clue works.
(Other definitions for schedule that I've seen before include "Timetable; plan of action" , "Plan for an activity" , "Timetable for activities" , "List of times when things should happen" , "List of duties, etc" .)