One of the first things new copy editors learn is that they should change the contraction 'til to the word till, or, in more formal contexts, until.
Then, if they're anything like me, they spend the next couple years running around telling everyone who'll suffer their company that the form with one L and the apostrophe is wrong, wrong, wrong. It takes no apostrophe and two Ls. End of story.
Eventually, the inevitable occurs: Someone, perhaps an editor who's been around the block a few times, points out that the rules of contractions mean that you certainly can use 'til if you want to. Though it's probably not a good idea. Because pros opt for till, the only people using ‘til are likely to be amateurs, which puts a serious blemish on 'til's image that can stain the image of any writer who uses it.