Mine best days are the middle of the week. Usually my views and sales are low on the weekends. Haven't been able to figure out why, but that seems to be the trend with me. :)
Maybe I promote more during the week, but I notice overall less activity in my shop during the weekends. That's alright though, I use my weekends to create since I don't have much time during the week because I work two jobs. :)
I'm fairly new, have been selling for a little over a month, but so far my "0 sales" days have been on Wednesdays and Saturdays. It's probably not statistically significant, with such a small population of data, but kind of interesting anyway . . .
My sales are almost always on a Tuesday or Wednesday. My weekend views have gone up this past month but still no weekend sales to speak of since I opened on Thanksgiving 2011.
It's tough to find a pattern for my shop. One week I might go several days without a sale and then get a few in one day. The next week things might be more even. I'm not sure if it's something I'm doing or if it's just random.