Question: how many hours a week do you need to learn a language?
Answer: They range from 900 to 4,400 hours. If you were to study a language on your own for 4 hours a day, 5 days a week, for a total of 20 hours a week, these estimates mean it would take you somewhere between 45 weeks and 220 weeks to reach B2 level of your target language. That is between one and four years!