Until, Till and Til

'Til versus until and till is often argued about in most style guides

–conjunction

1. up to the time that or when; till: He read until his guests arrived.

 

2. before (usually used in negative constructions): They did not come until the meeting was half over.

 

–preposition

3. onward to or till (a specified time or occurrence): She worked until 6 p.m.

 

4. before (usually used in negative constructions): He did not go until night.

 

Till is considered to be the abbreviation of until. And 'til, according to some style guides, is a mistake although it still shows up in advertising and on TV.

To stay safe, I'd stick with till or until.