In Britain during WWII there was “Double Summer Time,” which meant adding two hours to summer days instead of one. Although it may be assumed that this has nothing to do with the matter in hand.
“Double night time,” could mean that the Observers were on twice the pay they were usually on for working the night shift. Except that once the Supervisor makes the announcement all subsidiary personnel are released early, but their time sheets will be normal.
So why have 5 of the 7 Observers been released from the shift early? Possibly because they will not be needed, as imagine all the citizens, at least the troublesome inmates, have been put to sleep, sedated through their regular night cup of hot chocolate that night. So if one extends that for the next 7 days and nights you get double night time, the inmates kept under sedation all that time, the reason being that they will not cause any trouble while the real Number 2 is away in the Embryo Room for a week.
As for the citizens in ‘Fall Out’ being awake, they would have been awoken on the day the Supervisor let Number 6 and the Butler out of the Embryo Room, the week being up. And it must not been forgotten, that originally ‘Once Upon A Time’ was a stand alone episode, and not linked to ‘Fall Out’ the way it is. So the inmates who had all been kept sedated for a week, would simply be allowed to wake up and go about their business.
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