The Dreaded Half Day

This entry poses a simple question: Why do half days seem longer than a full day? We get off early the day before a holiday and these days just seem to drag on forever and I'm not sure why. It could be for an array of reasons. For one you are so excited that you get an extra day off that it makes you not want to be at work that much more. Then when you are expecting to have a half day you expect it just to fly by but then when the early part of the day drags on as normal, it just seems to take that much longer. And it's not like anyone really gets anything done on half day Fridays. We don't do much and certainly don't care to do much. So why don't we just take the day off, seems like the most logical conclusion.