Edds Day Counter adds a simple yet atmospheric way to see how many days have gone by in your Minecraft world. It scales with however many days have went by, so it should work on existing worlds.
Select version for changelog:
Changelog
No changes yet, just now uploading the addon to this platform.
Btw can you make an addon that adds seasons based on in-game days like the Java mod?
Like the reg day counter is just a static number on the screen, this happens when it turns day, and it just makes it feel more "alive" I guess.