The Monday 7 May 2018 CZ321 (scheduled 2100 hours from CAN to MEL) did not become airborne until 0003 on Tuesday 8 May. A333 B-5940 should arrive at roughly 1105, 145 minutes tardy. CZ344, the 1030 hours return should be able to commence pushing back at around the 1225 mark if all goes well.
Up north, it's a similar situation with CZ381, the overnight CAN down to BNE (B-1063) that is arriving at an estimated 0959 hours, 94 minutes late.
Making a threesome, CZ325 from CAN to SYD (A333 B-5922) is likely to arrive at 1157, 212 minutes late, so the worst of the lot. CZ326, the scheduled 1005 hours return will be unable to depart until at least 1320, so even if it picks up a little time it will still be badly late into southern mainland China.