deadsea - 6:55 pm on Jul 9, 2012 (gmt 0)
I can't imagine that most SERPs would benefit from being different at different times of the day. Maybe if the query is "furniture" and google wants to highlight office furniture during the day and home furnishings in the evenings. Even that seems like a stretch to me. Seems like home furnishings would be so much more popular that switching the SERPs up would be counterproductive, even during the daytime.
Alex, are you checking on two different computers, work computer at the office during the day, home computer in the evening?