With the help of the M&M's RM Brand Characters, readers will learn why people keep track of time, how they do, and whether a millennium is a really long time or not. . . . All leading up to answering the big question: why the calendar we use to help us keep track means that we have a millennium right now, and not some other time. Along the way, there are side bars and other excursions, into blue moons, the longest year ever (445 days ), and an explanation of why MM=2000.