Alright, so from a licensing perspective, either BSD (or the similar MIT) licence or Public Domain would be appropriate. BSD/MIT require keeping any existing author/copyright notices but allow everything else. Public Domain should actually allow everything with no restriction whatsoever. BSD/MIT are very common among open-source projects with a very liberal licence, and Public Domain is for instance used by the very popular SQLite project.
As for GitHub, I actually wouldn't need to maintain "my branch" of T-Clock. (I'm just a user who wants to see it working...) My idea was to find a place for the latest version of the code for every contributor to contribute to and hence for every interested user to get it from. I've seen three current contributors so far, one being you and the other two being the most recent patch commenters in this forum. I don't see myself as one of them so far. It would of course be most useful if everybody had access to this one location and GitHub could be it. (There are sure other sites like CodePlex and you name it, but my personal experience is limited to GitHub. Also, I'm not fully aware of how multi-contributor cooperation really truly works with GitHub, but at least one repository is certainly a start for it.)
Long story short, I'll just create a repo there, upload my latest build of it and publish the URL. You could then also use that link for this site and we'll see how it goes with further contributions and patches. No obligations at all.