In fact, this question mainly depends on your learning ability. If you learn quickly and understand thoroughly, you can learn it in a month. On the contrary, if you learn slowly, the interval will be longer.

In general training schools, the basic study time is three or four months. Of course, if you have a poor foundation, you can extend your study time until you learn. But if you want to learn from the bar master, then this time is not necessarily the case. Because your main energy is still spent on work, you have little time to study.