How Do You Know What Time It Is Author:Robert E. Wells Time is a mystery. And even though we can't see it or touch it, we can measure it--with clocks. But a long time ago, there were no clocks. Back then, people measured time by the sun. Egyptians were the first to keep track of time, with a shadow stick clock, and they were the first to divide time into hours. While clocks kept track of hours, th... more »e moon helped keep track of months. The first calendar was a lunar one, but it was soon discovered that it was not exact. The calendar was then based on the sun, and it was Julius Caesar who added a day to February every fourth year to make the calendar even more accurate. Robert E. Wells covers the history of measuring time with funny and interesting examples and illustrations.« less