In general Mandarin Chinese is more of a “sprint” than a “marathon” language, because it is very easy to forget words unless you hear/use/review them again quite soon after you learned them. That means it is usually much more effective to study more intensively for a shorter period than sporadically for a longer period. It is of course up to the student to decide on this and our Chinese school can offer any schedule a student wants. However, according to our experience, for any kind of real progress a student usually needs at least two sessions per week at two hours each session. Anyone who wants to make really quick progress towards fluency should consider at least eight hours of class per week. If there is a risk that you'll be out of Shanghai sometimes on business trips or holidays, then it might be necessary to schedule even more classes to at least maintain that average. What often works well in our experience is planning intensive study periods for a limited length of time. Many of our students spend a few months studying intensively to reach the Mandarin level they need, and afterwards start to focus again on other areas of their life - stopping or strongly reducing classroom hours. Doing an intensive Complete Immersion program in a smaller Chinese city for a week can also be a very effective way to get your Chinese ahead.