I wanted mine to be massive, big enough so you could walk on the arms as they went round and I was also keen that it use the Mojang supplied api, so I could create some re-usable functions which would no doubt be useful in the future such as:
The time is then updated by clearing the previous hand by drawing the previous line again but setting the blocks to air, and then recreating the new hand.
If you want know more about the minecraft api and a rather gentler introduction, check out this post, Raspberry Pi - Minecraft API - the basics.
Download and run
You can download the code direct from git-hub, so run minecraft, open/create a world and follow the instructions:
If you want to have a go yourself, try the following:
Copy the python api class library from minecraft to the programs directory
Create minecraft-bridge.py python program
or open Idle and save minecraft-clock.py to the minecraft-clock directory
Be careful cutting and pasting the code from a web browser and you can end up with odd characters in the program which will end in syntax errors.
The complete code repository is also on github, https://github.com/martinohanlon/minecraft-clock.
Note - minecraft must be running and you must be in a game
or if using Idle, click Run Module