I realise this question is rather broad, so I'll do my best to narrow down what I'm looking for as much as possible.
The big idea
The full daylight cycle on this hypothetical planet is consistent in duration, but it is made up of two smaller cycles that are not. Essentially, this is how it goes:
- First Day (~12 hours)
- First Night (~4 hours)
- Second Day (~12 hours)
- Second Night (~16 hours)
Following this the cycle loops around to the first day, and so on.
- The main question: what would a human population's sleeping schedule look like? Would they sleep once at the beginning of the second night, wake up in the middle of it, and sleep again near the end? (this is my current hypothesis)
- In a similar vein, if a significant portion of this human society were to be active in the middle of the night, would their activity be very different to what it'd be in broad daylight?
- Would this affect plant life in any way? (I assume not much, but just asking to be sure)
- What about animal behavior with things like sleeping and hunting patterns?
Some extra clarifications
- Assume the human population lives in some sort of medieval society
- Assume an earth-like planet for vegetation, climate, etc. (say the northern USA if you need a region)
- Assume a seasonal cycle like what you'd see in north america (clear separation between summer/winter, and consistent/comparable length of seasons/year)
- Assume that this cycle applies to a particular region and not necessarily the whole planet. I'm not sure how the day/night cycle would differ with seasons and lattitudes (I assume it would change at least slightly), but if you happen to have an idea I'd also like to know.
- I'm not even sure if such a cycle is possible, neither of what sort of convoluted astral combination you'd have to use (maybe with two suns or something?) but for the purposes of this question, assume it exists in at least one region.