CSC Light levels

The Computer Science Club of the University of Waterloo has a webcam or two.
By monitoring the average brightness and the standard deviation of the brightness of the image, I try to determine when the CSC is open.
Here is the data in bar graph form and fancier ``clock'' graphic form. With this data, I was also able to determine how much the CSC is open.
Here is the average for all days; weekends; weekdays; Mondays, Wednesdays and Fridays; Tuesdays and Thursdays; and individual days:
Monday, Tuesday,Wednesday, Thursday, Friday, Saturday, and Sunday.