• it depends on one’s country, state, city.
• it depends how many hours do you sleep.
• it depends how many hours you can study.
• it depends on your own health condition
• it depends on the environment you are studying.
• it depends on your own interest.
• it depends on your quality of attention towards study.
• it depends on how much you can grasp.
• it depends on your practice.
• it depends on your time management.
• Last but not least how you good you are at your studies & how you respect your families.

some study at night while others are sleeping
some study at day time for practice.