In its first weekend after release, Deadpool made an estimated $135 millions making it the biggest opening day ever for an R-rated film. This success pretty much meant one thing, Deadpool would be getting a sequel (cause when you make one good movie, you need to milk it for all its worth).
The official announcement of a Deadpool sequel came earlier this year, with two potential dates: October 6, 2017 and January 12, 2018. Apparently, the folks behind Deadpool are aiming to make the film available as soon as possible.
“The guys, [Paul] Wernick and [Rhett] Reese, are working on the script, and we hope to have a script very soon,” Kinberg told Collider during the 42nd Annual Saturn Awards. “We hope to shoot the movie sometime at the beginning of next year.”
If Deadpool starts filming early next year, say February, the film will enter post-production and might make an October reease, but that's severly pushing it. January seems more likely, unless FOX gave those dates away to another film.