They wanted to investigate how pressure of time can lead to stress, and to see how an environment without clocks would affect productivity. They say that time is money, and most companies use time to control their activities because it is easy to measure. On the other hand, humans have a biological clock which doesn't necessarily correspond to the standard eight-hour working day. We are more productive in the morning, and then our efficiency tends to drop off after lunch. So, if you're feeling hungry, why not have something to eat instead of waiting for the lunch break? Or, if you've finished your work, don't hang on until it's time to clock off, just go home.