I don't exactly have a strict schedule, more like a natural one. For some reason, it's always around 7 pm when I start drawing (I usually sleep at 5am, so it's not as late as it may normally be).
It can take anywhere from 10 to 20 hours to finish a strip, and it stretches out over a period of 2 to 3 days. As soon as I'm done with a strip, I have it in mind to start on the next one.
I'm certain that I can get them done a lot quicker if I stop getting distracted by the internet. It's a daily process, but I'd like to think I'm getting better at disciplining myself. I've begun to disconnect the wifi when I start drawing.
Like @Sketchmazoid said, there's not really such a thing as "own time" once you've dedicated yourself to making comics for a living. Making comics is your "own time."
The way I see it, I'm either working on my comic (either directly by working on it or indirectly by utilizing social media to gather more exposure or working on organizing ideas/scheduling the next strip or project) or I'm just wasting my time. I think successful creators are workaholics in a sense. They're always thinking about their creations if they're not working on them.
I recently gave advice to someone who wasn't sure of their career path. "If you want to make a living doing what you love to do, you better work AT LEAST twice as hard than the people who are taking the "normal" route." I dropped out of college to pursue my dreams, and I work harder than I would ever have in college because I know that it is necessary to succeed. I only leave my house when I have to. Sacrifice is necessary in order to be among the best at something. In a field as competitive as webcomics, you better be working your butt off.
At the same time, you have to know how to recharge your batteries. A lot of things in life is about finding the right balance between things.
I feel like this is the case with most comic artists, but finishing new strips has become my way of charging my batteries. I just feel accomplished and happy. I think you sort of become addicted to it.
...It's probably important to really like what you're creating.