There was a time when time itself was undefined...no one knew the difference between a minute, an hour, or a day. Then people began making tools to measure time using the sun, the moon, and water. Using this knowledge they began to build clocks and from that created calendars made up of months and years.

Learn about the different times of the day, and activities associated with each.

"What exactly is the difference between Eastern Standard Time and Pacific Standard Time? And why do they-and the 22 other global time zones-exist at all? In this fun, informative set, readers learn the answers to these questions, starting with the history of time zones that began with the American railroad lines. With content that supports social studies curricula, the main text is written especially for lower elementary readers. Colorful maps throughout...

Discusses the reasons for time differences in different parts of the world and the history behind the division of the world into twenty-four time zones.

Learn about the days that make up a week.

Learn about clocks and calendars and how they measure time.

How do humans perceive time? What are the three different kinds of days? What is a shadow clock and how does it work? Using easy-to-find materials, you can conduct these fun and simple experiments to learn about the science behind time and how it has been measured throughout history.