You might have to ask this question if you don't belong to a business oriented family, where a job culture prevail instead ... the answer is simple: i.e. the best time to start a business is when you are studying ... that is right !!! why? because this is the time you have the luxury to experiment lots of things without much pressure; and with a little common sense and smart thinking you can avert yourself from making a loss, let alone making enough for your pocket money (by the way there are lots of examples from PAF-KIET, check Established Business page on this website) ... On the other hand, when you are passed out, the immediate pressure from your family to get a good job will hardly let you experiment anything to establish your career as an entrepreneur.