Duty Time Definitions

[boofhead]

Considering Part 135 (USA) but probably similar to Part 121, if a pilot is on standby and is called in to work a flight, does his duty time so far as the flight is concerned start when he arrives at the base, and go for the full 14 hours, or is it dependent on when his/her standby period started?

[Check Airman]

At my operation (121) it starts from the moment I became available for CS to call me.

[boofhead]

So if you are on standby from 0600 your duty time starts and any flight you are called in for must have you back on the ground before 2000 (assuming a 14 hour duty)?