didn't seem so funny when dragon pointed out what could happen
It already is!
Dragon's example is easy compared to some of the crap CXFs fly already. CX -400Fs are flying 2 and 3 sectors up to max FDP all over the place, and where it's fallen over because of delays and crews not going into discretion they roster a leg stretch. ie. MIA-IAH-ANC which used to be 2 crew.
Other shockers on our back door.
HKG-KIX-ICN-HKG px last sector.
HKG-DAC-HAN-HKG px last sector.
HKG-CGK-SGN-HKG px last sector. I got called out on reserve for this, was a casual 17:30 duty !!!!!!!
The point is the whole time zone thing is flawed as the further north and south of the equator you fly (in an east/west direction) the more time zones you are able to cross in a single FDP.