30min-1h around that :) sometimes is better 30min focus and with energy than 3h without want do it

It depends on how long you are willing to take to learn the language and what you consider knowing a language to be. 

If you plan on spending the next 50 years learning one word and one expression a day and don't even care if you know everything, just want to be able to have a simple conversation or be able to sing some songs etc.... then 5 minutes a day. 

If you want to be able to understand everything said to you and in movies and speak with fluency in 3 months then you will need to spend most of your time in concentrated study and practice with excellent tools and have some natural talent to boot. 

My rule for myself is I do whatever I can until my brain starts to hurt and that has to do. :) 

at least one hour but regularily

I'd like to spend all my time {excpet working hours and sleeping hours} to learn languages.

The more the better.