Originally Posted by
clubord
This is completely incorrect.
There are no contractual "windows" built in for pilots to have the option to decline a flight. Quite the opposite, in some situations pilots may extend their duty to the maximum FAA Part 117 duty day limits. This situation happens on international weather diversions.
you two might be arguing over semantics.
Pilots have a contractual limit. Pilots can choose to waive this (presuming it is less than FAR limit).
Absolute limit is FAR 117 maximum, which cannot be (legally) waived.