Before I start, let me add the disclaimer that I am not a user of T-Clock and nor have I actually looked into the Github for more than 10 seconds before posting this.
Now that's out of the way:
The Github seems to be only the source code, and not the compiled version. This means that anything you get from Github will need you to compile it yourself.
There are installer versions available here: https://www.donation....msg197200#msg197200
- This is if you don't want to/Don't know how to compile it yourself.
This is simply to give you a quick answer whilst you wait for somebody more familiar with T-Clock to come along