There's a good chance you were already well aware of the dangers of not sleeping well, but the latest study coming out of Microsoft's research organization is giving you some data to really back it up. Microsoft performed the study by analyzing the keystrokes and other activities of people who were using computers during their habitual sleep patterns. Unsurprisingly, the results showed an incredibly sharp decline in performance of users who were working late at night.
The study showed that your best performance comes just after waking up when the local time is around 9 a.m. That quality of work persists until about 4 p.m., where performance really starts to trail off. At its absolute worst, keystroke time at around 5 a.m. spikes all the way up to 270ms - that's compared to just over 200ms, at best.
The study falls in line with the data that's previously been presented by more controlled lab studies, which should give you an idea about how much mind you should pay the numbers it provides. The seeming success of this study should also serve as an encouraging factor to those who are considering performing similar studies in the future.
If you're looking to learn a bit more about the study, you can see the research presented in full at this year's World Wide Web Conference.