I leave it in the primary 3-4weeks, then keg. I still do use a secondary though.....secondary for specialty beers, dry hopping, or adding fruit. Not discouraging you from using a secondary, especially if you need the primary for a new batch. To answer your question, if you want to secondary leave it in the primary for at least 7-10 days then at least another 7-10 day in the secondary, then bottle/keg as normal. I have did it this way for years, unless it was a higher gravity beer or lager.