I recently picked up another Stuart J. Murphy MathStart book, this one covering the concept of time. We wrap up third grade math with a measurement unit, so I'm looking forward to using this story in March.
Game Time involves a championship soccer match between the Huskies and the Falcons. Throughout the book are numerous examples of measuring time. Time is measured in weeks, days, hours, minutes, and seconds. The book also demonstrates the relationships between various units of time. The story of the game is engaging, with the two teams battling right up until the end. I definitely recommend this one for your study of time.
Here are some other good books dealing with time concepts:
And, a link to my elapsed time game available in my Teachers Pay Teachers store: