Hello, thanks for posting, it’s something that I’m aware and i will try to improve. But it’s totally unnoticeable at game speed, only when accelerating the time it become noticeable. For now you can set to higher latitudes that it will be less noticeable.
In theory i know why this happens, it’s because the sun rise and set through a linear function. I should change that to a non-linear function like a quadratic function or something like that.