For mine i notice its always pretty slow on the weekend. Usually the only work i get is sometimes from DP. But hardly ever get any work from my site. Then around monday night it picks up again until saturday morning.
Things are usually slow on weekends and holidays for me. I guess people are spending more time outside or with families instead of surfing the internet.
Definitely weekends, holidays, and usually the end of the month are the slowest sales periods for me; when things like family commitments and financial issues come into effect
my affiliate sales are sporatic, but there doesn't seem to be a preference between week days and weekends...
I continuously work no matter if it's busy or not. The weekends tend to die down a little when it comes to traffic, but no real big decreases really.