Clock time
Clock time is the wall-clock duration of a flight, captured as two timestamps: off blocks (brakes released, starting to taxi) and on blocks (parked, brakes on). The difference is the block time, and it includes taxi at both ends.
In Syndik8, clock time (the block time measure) is one of the measures a usage log can capture. A syndicate ticks which measures the log captures (engine meter, block time, airborne time, in any combination), and the billed measure decides which one drives the hourly charge.
Block time is the wall-clock span including taxi. It is distinct from airborne hours, which are measured separately from the takeoff and landing times. Taxi minutes are not subtracted from block time for billing; they only prefill the bracketing times on the log.