Until further notice, tech stocks are off limits unless they pass the Jim Cramer test, Cramer told viewers of his "Mad Money" TV show Wednesday. The best way to trade tech stocks is by following the calendar, he said. And right now, the calendar says it's time to sell tech. Everybody on the Street knows about the calendar, and most money managers defer to its wisdom, he continued. The secret to tech stocks is that they are seasonal. You sell them in January, you buy them in August, and hold on to them until mid-December, he said. If market players get lucky with a certain tech stock, they could hold it even until mid-January. But no longer, Cramer warned. Though he believes that people should consider getting into other sectors during this time, Cramer said investors shouldn't necessarily sell all of their tech picks because of the calendar. "Discriminate and find out what part of the tech sector is getting damaged," he said.