Comes the Krampus!, he said, should enter production after Smith wraps on Clerks III, which he hopes to start filming on April 7.
That's awful specific for an idle hope; sounds like he's got a start date unless somebody has a last-minute conflict or something.
Clerks II was filmed from September to November 2005, and released in July 2006 theatrically. Clerks was filmed over the course of three weeks (with two pickup days); Wikipedia doesnt' say exactly when, but given the magazines on the newsstand in the film, it seems to be around April 1993, as a magazine cover featuring Brandon Lee, who was killed on the set of The Crow in March 1993, is visible. That film was released theatrically in October 1994 after having screened at the Sundance Film Festival the previous winter.
Assuming a fairly similar production/release schedule, it seems likely the film will see a spring 2015 release. Clerks III is expected to be distributed via mainstream channels, rather than brought around the country roadshow-style as Smith has done with recent releases Red State and Jay & Silent Bob's Super Groovy Cartoon Movie.
It's not yet clear what the plot will entail, or whether Rosario Dawson will reprise her role as Becky, the woman to whom Dante proposed at the end of Clerks II. Brian O'Halloran and Jeff Anderson will return as Dante and Randal, with Kevin Smith and Jason Mewes presumably returning as Jay and Silent Bob.
At this year's Sundance Film Festival, Smith hosted a "Class of 1994" special screening of Clerks.