Information

Minecraft version: 1.19.2
Modloader: Fabric
Fabric loader version: 1.19.2
Environment: Singleplayer
Mod name: GUI Clock
Mod version: 3.8

Description

After around 80 days, the clock reset to Day 0. This happened twice, once in my creative world and once in a survival world.

What do you get when you run /time query day in both of your affected worlds?
If they both return 0 as well, try running /time add 1920000 (/time add 80d) on each of them to bring the day counter back to where it's supposed to be.

Can you try what @James103 suggested?