When I tell people that I write novels, the usual response is "I want to do that someday. When I have time." I always smile and feel a bit sad for them. That novel, which is probably a really great idea, is likely never going to get written. The thing is, no one has time to write. Between your day job--and every author but the few millionaires out there have a day job--family, kids, friends, house work, etc. there is just not enough time in the day to write.
So how do I manage to do it? Well, you see I have this stop watch with the magical ability to replay time and... no wait. That's from Harry Potter. I guess I just make the time. Writing is very important to me, and so it's not a difficult decision for me to do it instead of something else. Usually that something else ends up being cleaning. My place is a mess. Really, you have no idea. Unless you've been in my house and then you have some idea.
Being able to find the time is what separates those who want to write with those that do. It's something that you have to figure out on your own. Maybe you work best at a certain time of day and for a couple of hours each day you lock yourself in a room and work your butt off. Or maybe you work in fifteen minute clumps broken up throughout a very busy schedule. For me it's somewhere in between. I try not to limit myself to only being able to work under one condition. That becomes very limiting and can stifle my creativity. For example, I like to writing on the computer, but I always bring paper and pencil with me anywhere I go and often end up writing a scene or idea in between classes or on a break from work. I could take my laptop with me, but I find writing on paper is sometimes a nice change and can help me look at the story in a new way.
For me, the question isn't when do I have time to write, since I always seem to find the time. Instead, it's when do I have time to do anything else?