How many hours a day do you spend on your target language?

I usually spend 1-2 hours. Any more than that and I get too tired. At my pace it takes about a year and a half to 2 years to get to where I can read and listen. But I reckon it could be cut down if I was spending more time a day.

I heard that training diplomats spend 8 hours a day on the language they're learning: a full time job. Imagine that. I'd be completely exhausted and my brain would be buzzing by the end. You reckon you could do that?