This timer is perfect for speed runs. It is easy to use and set-up.

How to enable it in your world:
1. Create your world
2. Import the Datapack in the process of creating your world or drop it later in the folder "datapacks" (.minecraft > saves > [​your world] > datapacks)
NOTE: It may say that this data pack is created for older versions, but it should still work
3. Then simply rejoin the world and all the functions will be automatically displayed in chat
4. To use any function, just simply press the buttons displayed in the chat (forget typing commands manually)

Texture pack is not included with this data pack due to copyright material

Enjoy :D