One of the most frequent questions I get asked is about how I write when I have a day job… a question I’ll get even more now that I have a child. My answer is that there’s no magic to it. I just make time to write and am patient. I write a few hundred words a day, wedging it in among the other things I do. I watch a novel grow over a period of months until I have a draft, take a week or two off, then go back and begin revisions. The revisions proceed at the same pace. It really isn’t as slow as it sounds. I can finish a draft in nine months, revise for another nine, and produce a novel every year and a half — about as much as I could foist on the market anyway.
One of the biggest cliches in the business is that “writers write,” but I’m not sure there’s a better answer to the question. Writers are jotting down sentences over breakfast, dribbling butter on the pages from their English muffins. They’re pounding away on Google docs over their lunch hours. They’re scribbling in notebooks in the parking lots before they drive home. They’re clattering on a laptops during their TV hour with the kids.
It’s not always easy, but it’s usually not impossible.
Kurtis Scaletta's Site 
I like the picture you paint of writing in the wedges…that is so true! As a mother of four running hither and thither, I write on stolen time all day long. But, you’re right — it’s not impossible, and I will try to remember that on the days when I don’t feel like wedging it in.