Firstly I'm really interested in the way your mod works and I think you should add/modify some parameters:

• Replace "Min Day Length"/"Max Day Length" with "Winter/Spring/Summer/Fall Daytime Ratio", night is when light is below 50% and day when above, the ratio is given using a float number, 0 mean no daytime, 1 mean no nighttime (can have a bit of dawn/dusk depending of next setting).
• Add "Winter/Spring/Summer/Fall Transition Ratio", 0 mean dawn/dusk are
  instant, 1 mean dawn start at end of dusk and dusk start at end of dawn.
• Add of "Winter/Spring/Summer/Fall Day/Night Light Level" which would permit to simulate what we have at poles with a sort of permaday and permanight with some little variations.
• Add of Day Length (actual length from midnight to midnight), this value
  should be exprimed in ticks.

here is what I would expect as a reaction to settings modifications (here a single day) https://www.geogebra.org/m/f2tDDTMf

The concept of Seasons is only there to allow more precise tweaks and allow variation of transition through the "year".

How does the settings work? in the Latitude -90 ~~ +90 Which mechanic does it work?

Latitude is where you are on the planet, north to south. If you're in the arctic circle there will be some days of the year with no daylight, and some with no night.