“Digital computers are synonymous in the popular mind with precision processing of information. However, when it comes to the basic information processing task of keeping time, they often perform worse than expected. To see how bad computers can be, consider some things that are better at keeping time. The gold standard in timekeeping is the sundial, which is a perfect analog timekeeper. However, sundials are not very practical and are not used to keep time on computer networks. The U.S. government, for instance, often needs to run its computer networks at night or on cloudy days.”
—How Many Seconds in a Second? Michael Hsieh and Doug Wood, FDD