But for the first time we have a clear idea how the worlds largest cannabis market will be regulated and licensed, Clark said. For medical marijuana users in California, the proposed rules will have no immediate impact. The draft regulations are expected to take months to review and refine. They do not go into effect until Jan. 1, when recreational marijuana use also becomes legal. The 58 pages of draft rules provide insight into the massive job ahead, as the state creates what will be a multibillion-dollar marijuana economy. There have been questions about how the state could quickly review and issue licenses for tens of thousands of growers, sellers, manufacturers and distributors after the regulations for medical and recreational marijuana kick in next January. The answer: The state will need some time. Applicants can stay in business indefinitely while the review is underway, providing they were operating prior to Jan. 2, 2018, and submit a completed license application no later than July 2, 2018. The proposed rules vary widely, from the obvious to arcane.