Sorry if I wasn't sufficiently clear: I was referring to my post above. Till is perfectly good English in precisely the sense used in the review above, and using till in that sense predates the very word until.

It's not actually a typo, a mistake, or a made up word. The mistake is to think till is a contraction of until, as shown above.

"In most contexts till and until have the same meaning and are interchangeable. The main difference is that till is generally considered to be the more informal of the two, and occurs less frequently than until in writing. …Interestingly, while it is commonly assumed that till is an abbreviated form of until (the…