So I found some relevant info at http://www.electronics.dit.ie/staff/tscarff/Music_technology/midi/MTC.htm
I also found a post from 2012 with some example code: Sending midi (clock) from standalone app?
I took the liberty of uploading it to Github: https://gist.github.com/adamski/b42eb8f91910fe28a017458e2edad5d3
That looks like a like very good starting point at least.