Ballet dancer unceremoniously ditches belt on schedule (8)
I believe the answer is:
calendar
'schedule' is the definition.
(I know that calendar is a more specific form of schedule)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for calendar that I've seen before include "Chart showing months and days" , "Table of months and days" , "List of dates of land race" , "list of appointments" , "Date chart" .)