Flight duty time:
Flight duty time is the total time commencing from the time of reporting at the
airport for the purpose of operating a flight and ending with the termination of a
flight or a series of flights (chocks on plus 15 minutes).
This is from AIC 28/1992 which deals with FDTL.
AERONAUTICAL INFORMATION CIRCULARS
Usually the reporting time is one hour prior to departure of the flight.