This is my timer, especially for challenges. It will stop your used time in the format hh:mm:ss. This is not meant for larger times like days or weeks.

How to use:
1. Create your world (e. g. for a speedrun)
2. Import the Datapack in the progress of creating your world or drop it later in the folder "datapacks" (.minecraft > saves > [​your world] > datapacks)
3. Type "/reload" in your world chat
4. You can start it with "/trigger challenge_start"

The pictures above are in German, the Datapack is in English. "Timer: pausiert" means "Timer: paused". I didn't implemented a pause function so when its started, you can't pause it while you afk or something like that. The timer will stop when you die or when the ender dragon is dead.

One bug (and i don't know how to solve) is when you bedbomb the dragon, the timer wont stop, because the dragon is not killed by a player.

To restart the server from 0:00:00 you can start with 3. in the instructions.