Think there are 4 flights a day to SYD, every one of those has a layover in the 18-30hr range.
Umm, the 18-30 hour rule only applies where the crew member is unacclimatised. Not sure how a HKG based crew member become unacclimatised during a flight to SYD when the maximum time difference between HKG and SYD is only 3 hours??