Sgt_Kickaxe - 7:08 pm on Jun 11, 2012 (gmt 0) [edited by: Sgt_Kickaxe at 7:09 pm (utc) on Jun 11, 2012]
It actually began late June 5, early June 6 and something that happened, at least to me, is that my peak traffic days have shifted, again.
Eons ago: Thurs to Sunday were the weekly peak traffic days.
3-4 years ago: Sat to Monday became the most trafficked days.
Last year: Sun to Tuesday was the peak.
As of June 5/6: Monday to Wednesday is the new peak, from Google.
Now, I know the entire internet didn't shift how often they use the internet on June 5/6, or likely any other of the times above, so something Panda can do is place your site on a different traffic "schedule". (unless Panda isn't the only "change" Google just made)
We've been thinking of rankings as static, you get x% of the searches for your keyword based on your rank, but that's NOT how the internet works anymore. The rankings are in flux depending on site type (informational vs transactional vs locational) and day of week, keep that in mind with any report you make here... please.
[edited by: Sgt_Kickaxe at 7:09 pm (utc) on Jun 11, 2012]