Overnight turnarounds
 

Hi! I'm an aviation enthusiast, so I don't know much about pilots' shift types. The question that interests me the most is: there're numerous flights that leave the base airport late at night, and fly back early morning with an overnight stop at a destination (for example, NZ573-NZ582, a 7-hour overnight stop). Are those flights flown by one crew, or is it more likely that another one flies the aircraft in the morning?

Short answer is 2 crews for that. Minimum rest varies, depending on the length of the previous duty and on the rules of the particular regulating authority, but the shortest would be about 11 hours.

There is also the option of a single crew doing both the late arrival and the early departure flight by the use of “Split Duty”, which involves two periods of duty separated by less than the minimum rest period. Special rules apply.

Another possibility is the “Standover Day”, where one crew arrives on the late flight, a second crew is already there and does the early departure the following morning, and the first crew have a day off down route before operating the early flight home on day 3.

I've not had much to do with scheduling, but what often happens if an airline operates more than one flight a day is that the lare arrivinf inbound crew will operate an early afternoon flight the following day and the crew from that will leave early the following morning. This means that the airline has to pay for rooms for two sets of crews. Stabling away from base is expensive but worth it commercially. The alternative as the last post says is the standover day. This explains why if you have serious disruption such as fog on one days you will often get cancellations on the following day (or in bad cases days).

With a Europen legacy short haul rosters may comprise three flights on day 1 (such as LHR-GVA-LHR-ZRH) and then day 2 might be ZRH-LHR-BSL-LHR (a made up example). Patterns might be longer lasting several days. European low cost carriers are much more out and back as because they have bases in several countries there is much less need to outbase staff - it is also one reason why their costs are lower. American carriers can have very complex patterns.