Drawing custom ticks in the time line

[dgovil]

Was just wondering if anyone had any luck drawing custom elements into the time slider without implementing a new slider.
Something like how grease pencil can draw into it.

I was thinking it might be possible if there was somekind of paint signal I could hook into and draw accordingly, but I can't seem to find anything in the docs.
Anyway just wanted to check if someone had any success doing something like this?

Cheers