I've recently started taking my showers at night instead of in the morning, and I like to let my hair dry for a bit before I go to bed. For the last couple of weeks I've taken to knitting or scrapbooking during that hour.
Before that, I used to knit in the car when I was waiting for DH. If we happened to be out and about during the kids' naptime, if they were sleeping in the car, then I could knit while DH would run into the store for whatever it was we were there to get. When the baby was younger, I spent a lot of time knitting in the car, but now that she is older, not so much.
Other than that, all of my knitting is in public while waiting for one thing or another. I just have too many other things to do at home, including an afghan that I am crocheting but is too big to take around with me.
I've read some posts where people are self-conscious about knitting where other people could watch them, but between reading lots of Agatha Christie/Miss Marple stories when I was a kid and the crocheting I used to do whenever I was at some get-together with the in-laws, it doesn't bother me to have people watch what I'm doing, even when I frog!
To answer the original question , about an hour a day.