As far as the National University of Singapore is concerned, it is very difficult to graduate with a doctorate. You need to publish two academic papers in big journals, one of which has some research results and academic weight. This may be difficult. Many people go to school at 10 in the morning and go back to the dormitory at 10 in the evening. It takes at least four years to graduate if you work hard every day.

But getting a doctorate shows that you are very good. Study hard, graduation should not be a problem.