A good answer is between six months to one year; however, this is very dependent on the number of resources you devote to your plan, the level of competition, and what other competitors are competing. The days of building a website, optimizing title tags, and achieving lofty placings in a matter of weeks are long gone. You can't expect a website to rank for contentious search queries immediately after its launch. Google grades fitting sites with authority over time; thus, it takes some time for a webpage to function naturally. You must work hard and earn your way to the top of Google.