This year? Maybe never?
My logs showed a completely normal Friday for me whereas actual clicks & Page Impressions were the second worst day of the month and that's against a Sunday!
This last couple of months my Friday figures have shown no consistency whatsoever other than inconsistency.
It is now my second lowest day of the week even though my logs show me that I have an average of 90% of Monday to Thursday uniques/my impressions.
What are they doing?