At night while watching TV and early mornings on the weekends. When I really need a sewing fix I take a vacation day from work and devote the whole day to quilting.

For me its between 5AM and 1 Ken's at work then

I don't like sewing evenings either, I think its just the lighting.

I work full time so i sew for a few hours in the evening, but Sunday is my main sewing day.

I quilt in either mid-morning when I feel best, or later after my medically necessary long nap(2+hrs) when I feel better too. DH and I have come up with a great little routine, almost daily. When he comes home from work, he plays with our happy-to-see him puppy, then he relaxes at the piano and I quilt while enjoying his music. That's such a great 15-30min! My main problem is that with my stupid health I can never plan on a day of quilting since how I feel each day is unpredictable. Yesterday, I couldn't quilt at all. I'm going to try now when I sign off before something goes wrong. It's fun and very satisfying to see even a little creative progress made.

I always have a hand piecing or applique project on the go, whatever else I am making by machine, and I get most sewing done on those in the evenings, in fron of the TV. I can convince myself that TV time isn't wasteful if I'm quilting too!
With my machine made projects, it's just at the weekends I work on those and I'm an early morning person too.

On weekday, it's evenings after work and dinner. On weekends, I usually start around 2 or 3 in the afternoon and continue through til bedtime.

I sew whenever the moods strikes so I don't have a set time. One thing I love about getting older, I do what I want when I want. :D

Well, after reading all the replies, and going me? not me? finally decided, I too am an unpredictable sewer, depending on body.
But, I seem to sew MOST, on a good day, after breakfast and housework.
I finally realized, that if i walk into home-cave and switch machine on, then sewing is going to take place. If I don't switch it on soon, I will end up distracted messing and gauming with all kinds of stuff in there, but no stitches get made.
I feel especially good after putting a few miles, or even a quarter mile, on my machine. :D

Machine: 8pm-midnight . . . after the kids go to sleep. I try to do some hand-quilting or applique if I can a few days a week. My boys are 3 & 5 so it's hard to get uninterrupted time during the day.