It took about 10 days to two weeks for me, Matt. I remember being pleasantly surprised at how quickly it had started working compared to an anti-depressant!
Oh you know, I'd been declining Seroquel for about 3 years until I finally decided to give it a chance. The thing is, you don't risk becoming addicted to Seroquel, should you decide to take it, as you would if you were taking Clonazepam, for example.

I've noticed a change in two days, btw, since I started taking a half in the morning before work.