Day Counter is a fully customizable Minecraft mod that tracks the passage of time in your world and brings it to life. It adds a whole new layer of progression and atmosphere to your gameplay.
V6.0
Here you can see how it looks like in-game. All of this you can customize.
Here you can see the commands.
Here you can see how to craft the Calendar item. And this work back too.
Here you can see how to craft the Calendar Block