It's a Third 'Till

Why don't we use thirds with time? We say it's a quarter 'till, or it's half past, but nobody (except maybe for me) uses thirds. And why not?

Screw with people's minds! (That's what they're there for.) Start using thirds. For instance, right now, more or less, it's a third 'till noon. And at a third after four this afternoon, I hope to be working on the fog machine. Ain't language great?