At work, 8 hours a day, I play with Ruby code. Well mostly Ruby code. I also play with lots of SQL queries, some funky survey-collection languages called Blaise and Manipula and Cameleon, SPSS code, old legacy MS DOS batch scripts, a few old Python scripts, a couple Perl tools, and a few websites worth of CGI and HTML. And it's pretty fun. I couldn't ask for a better job.
And then I go home, at around 5. Assuming I can stay awake until midnight, that gives me 7 hours at home each night. One hour is taken up by cooking and eating. Add in another hour maybe for catching up on forums that need posting to and news sites and web comics that need reading. Let's give at least an hour or two talking to my girlfriend.
Assuming I do nothing else, e.g. reading some books I've been wanting to read, or playing a video game or two, that leaves me maybe three hours of "free time" each night. Assuming I can even stand to look at a computer screen full of source code after doing it all day, how in the world can I get anything productive done in three hours? I have all kinds of ambitions of things I want to do away from work. I'd love to contribute to some open source projects. I have ideas of projects I want to start on my own, some of which I have actually attempted to start in the past but lost interest. It's hard to stay motivated on something or keep an idea in your head when you can only potentially work on it on Saturdays and Sundays. I have two web sites including this one that should be updated much more frequently than they are. Etc. etc.
Where do people find the time to churn out large-scale, quality open source projects outside of work? I really wonder. Is it all college students working on them? Unemployed people? Or are people masters of multi-tasking and time-management?