Did you ask yourself that question? Did you even stop to think about it before you jumped into learning Chinese, Japanese, Thai, or whatever language you are learning? How many hours is it going to take to learn a new language?
There are more people who know WHEN they want to be able to speak a second language than those who know how long it takes to reach that point. They want to speak NOW. Or they say want to reach basic fluency by New Years. But they haven't even researched how much time it takes.
If you don't know how much time is required to reach your goal, how do you know if you are putting in enough time each week to reach it by your desired date?
Do not most language learners underestimate the amount of time necessary to learn a language? After all, it is not an endless process. Not being able to see the end in sight is a sure way to lose your passion. It leads to lost motivation and time spent away from doing what it is you need to do to learn that language.
The time required is different for each person because it is based on linguistic as well as cultural factors. I have found many references that state it takes 2,000 hours to learn a language like Chinese for a native English speaker. ALG World found that it takes about 1800 hours for Thai (if you do it correctly) plus a year of partial immersion in the country.
Will the TV method be the same? I can't say. But I have set my sights for 2,000 hours. Until I reach that figure, I won't be worrying about speaking or fluency. I hope that will take me above 90% understanding of the language while watching TV dramas. If not, I will just keep watching and I will let you all know when I get there. At that point, I will seek out opportunities to speak.
For sure, I haven't grossly underestimated the time it will take. Such as thinking that it's only going to take 300 hours, and thinking that I can put just 1 hour a day into it. When you realize that it's a big project, then you have a better chance of reaching your goal.
Another thing that helps is when you feel that this language learning is the most important thing you are doing in your life and you don't want to let anything get in the way. If you don't feel that way, then surely life will get in the way.
At some point, you can reach fluency in the language. You may not know every word you read, but you will have the knowledge you need to fully participate in that language. At that point, language learning is not so important and you can let something else take precedence.
So, do you want to be learning this language for decades? Or do you want to put your time in now and get it done sooner? 2,000 hours can be completed in just 2 years with a solid commitment of 2 and 3/4 hours a day, every day. Or you can reach the 2,000 hour mark in 1.5 years with a daily time requirement of 3 and 2/3 hours.
If you are learning a difficult language and say that you haven't enough time to devote to it, then perhaps you would save yourself many hours of struggle by quitting now. If you cannot quit, then you can save yourself many decades of suffering by doing it right and putting in the hours necessary up front. It does take a lot of input. Native input produced by native speakers.
Remember, there's a right way and there's a wrong way. And then there's MY way.