The Clock We Live On
I'm sure that I learned about Leap Year at an early age, like most people. But I never knew the details -- Caesar and Sosigenes, the longest year in history (46 BC), Julian and Gregorian calendars, etc. -- until I read The Clock We Live On.
When I was in San Antonio last year, I noticed this book off in some corner of my mother's house, its pages yellow and crumbling away. It's never good to throw away a book, but this one's time had come (note the tape; it had long been worn from use). Still, I remembered it so fondly that I saved the cover. The inside cover has an example of my father's handwriting, something I don't have too much of, so I wanted to save that too. Apparently he bought it in 1963, the year before he died.
I first read it in 1977. Besides the story of the western calendar, there was plenty of other interesting topics -- why days have 24 hours and hours 60 minutes, the development of clocks and chronometers, the establishment of meridians and time zones, and so on. The calendar chapter formed the basis of an oral report I did in high school Latin class.
Strangely enough, Ann brought home a book from the school library the other day: Venus: A Shrouded Mystery, by none other than Isaac Asimov. Late Asimov (1990) and a book for kids. But maybe that's not so strange. The man was a writing machine, even back in the days of typewriters, carbon copies and human typesetters, so probably a lot of his books are still stocking school libraries.