I agree with both posters above.
And May I add that when you leave a page opened for a long time, the clock can be slightly off (maybe 1minute or so). I think the clock is only accurate after loading a page, and if your computer is slow, or working on different tasks, it can slow the clock down (so it shows 7:59 when in reality it is already 8:00).
"Air is beautiful, yet you cannot see it. It's soft, yet you cannot touch it. Air is a little like my brain." - Jean-Claude Van Damme