Using a different timestep seems to have different effects.
Currently, I'm in my 2nd year of a 5.42 game and hurriedly trying to prevent my empire from getting in debt.
I have one non-homeworld colony in the same moon system as the homeworld.
The construction interval is 86 000.
There is this very curious effect.
My income is net +10 to +40 per 24 hours if I use auto-turn and hit 8 hours.
My income is -20 to -30 per 24 hours if I use auto-turn and hit 1 day.
After watching my civilians run about for a few weeks in game, I think I've tracked down the problem.
Essentially, whenever cargo freighters dock at my homeworld to pick up infrastructure, they take 1 time step to go from [move to colony Nilosia] to [Load trade goods at colony Nilosia].
If I hit 1 day, that is 1 day, if I hit 8 hours, that is 8 hours.
So I'm currently playing at 8 hours timestep since that's the only thing keeping my empire above 0 wealth (currently at ~40 wealth)
At least until homeworld runs out of infrastructure, but I should have the next economic tech done by then.
Is this behaviour a bug? Or just a necessary concession?