I'm an illustrator working from home, so the amount of time I have to work on my comics is a bit different than most people's. Also, how many hours a day I spend varies depending on where in the creation-process I am.
Storyboarding usually takes me a day or two per chapter - and by that, I mean I spend 8-9 hours a day on the storyboard for the days when I'm working on it. After that, I spend a focused day or two doing full-sized clean sketches and laying down the speechbubbles - again, 8-9 hour days, if not more.
After that, I fall into the pattern of inking a few pages, then going back and colouring the first one - then going ahead and inking one-two more pages, then going back and inking the second page. And so on until I've worked my way through inking the entire chapter, and it's time to start storyboarding the next one. Inking takes me about 1-2 hours per page, depending on complexity (some of the crowd-scenes/architecture-heavy pages take me more than that), and then I spend 2-5 hours colouring, again depending on complexity.
Once I get to the inking/colour stage, I tend to spend the morning of my update-days - Mondays/Fridays - colouring/finishing pages, so that I stay ahead with my buffer. I could afford to skip a few days - I have a 50+ page buffer - but I don't, because I like knowing I have that many pages in case of emergencies.
But yeah. I usually spend a couple of hours every day working on comics - sometimes it's my main comic, sometimes it's extras for the main comic, sometimes it's entirely separate projects.