Like 99% of us here, I work full-time in a non-programming role.
I don't think that number is even remotely accurate. Have you ever started coding on Friday night and not slept till early sunday morning?
No. First of all, I'm in the alleged 1% who does do software development for a living. Second of all studies have shown that any programming done above on average 40 hours a week, is effectively wasted, as the result is such poor source code, it will have to be rewritten anyway. With that in mind, and considering that actual programming takes about 20 hours of my 37 hour a week job, that leaves roughly 20 hours left for spare time programming, which is usually done in evenings, as having a weekend with nothing else to do, happens about once in a blue moon. Although overdoing it may be necessary to meet deadlines.
If that's true, you need better planning. Again anyone who's been through crunch time will attest to this: While you do work for longer periods of time than on a normal schedule, the actual amount of elegant, usable and maintainable code, is dramatically reduced, because as you start getting tired you start making more and more stupid mistakes, and the worst part is they may not get caught in time.