Who runs the world at Saturday night?
Or an airline?
When a captain is aboard a plane in flight, BUT has been asleep for hours, plans on being asleep for hours and is naked between the sheets in crew rest, who then is in command - that captain, or whatever pilot actually is awake, physically in cockpit and sitting in the left seat? And does a pilot sitting in left seat while a captain is in crew rest have to be a captain as well? Does a three pilot crew have to be 2 captains and 1 first officer?
A plane flies for 19 or so hours at most, but an airline never lands. There are always some planes in flight at far ends of the globe. Someone on ground has to give advice on diversions, consult engineers, consult with physicians, contact foreign states and airports for overflight and landing permits, arrange for visas, hotel accommodations, medical care... make decisions on behalf of the airline which may cost or save large sums of money for the airline, and lives of some or many people.
Who are awake at night in an airline? Cannot be one person, precisely because they need sleep, days off, vacations etc. A number of people must be involved... but in the morning when people get up, read news headlines and go on their business, are the people awake at night treated as underlings and menials? Or are they fully respected?