"Narrator Albert Einstein takes kids through time--literally. Measuring time is explored, from the stone circles and giant pyramids of ancient cultures to hourglasses and sundials to early time pieces and watches to atomic clocks. This explains why there are 12 months a year, 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute. And seven days in the week. From Stonehenge to Greenwich Mean Time to James Hutton's Deep Time, the book helps kids understand the passage of time, and why sometimes it seems so slow and other times way, way too fast." -- Publisher.