5-7 hours. (Full time job)
Depending on side projects add another 1-3 hours to that.
I wouldn't really put a time frame on it. Just think of a project you want to build and work on it when you get the time. I usually end up spending every waking hour on a project until I get a solid base. After that I try to work on it for an hour or two every night.
Cheers!
