In a blog post announcing his decision to film the upcoming holiday-anthology-horror film Comes the Krampus!, filmmaker Kevin Smith told fans a projected date for Clerks III to begin production.
He noted Comes the Krampus! should enter production after Clerks III has wrapped, which he hopes to start filming on April 7th 2014.
So far it is all speculation sprinkled with "if's" and "but's" but it sounds like he’s got a start date— unless something last-minute conflicts the rough schedule.