Default month duration isn't 9 days?

[Heiress]

As I understand it should be, but if that is so then why

Is it the 11th.

I shouldn't have messed with any settings accidentally nor does it show any unexpected altered gamerules when I hover over the world in question.

EDIT: Ok so this appears to be caused by a mod, but I have no idea which mod would cause this, what kind of mod changes this stuff?

EDIT2 Electric boogaloo: Ok I figured it out, its not caused by any mods at least, I'm fairly sure I think its not.

So when you create a world and make a creative world AND THEN DIRECTLY CREATE THE WORLD your world will have a 12 days per month

BUT if you do edit the gamerules then you get one with 9 day months as usual, the same goes for other gamemodes as well, the world in question is one in exploration mode, which explains why it has a 12 day month cycle instead of 9 day month, I must have created it directly without altering any gamerules.

Edited August 12, 2021 by Heiress