Monday, February 25, 2008

It's a Leap Year!

2008 is a Leap Year! Our calendar, the Gregorian Calendar, is based on a solar year which has always presented a problem, because a solar year is 365.24219 days long. In 46 B.C., Julius Caesar tried hard to make a calendar that would fit neatly into the solar year. He devised a plan whereby an extra day would be added every four years. Do your math--that means he was "rounding" the number to 365.25 days. It's only a slight difference, but after awhile, it adds up. People found that what were once spring holidays became summer holidays. So, by 1582, Pope Gregory XIII realized something had to be done. He came up with a complicated system. His calendar still provides for leap years every four years, but with a twist. If the year ends in 00, it is only a leap year if the year's number can be divided by 400. That means that 1900 was not a leap year but 2000 was. His calendar was so accurate that it was eventually adopted worldwide and is the calendar in use today.

Celebrate Leap Year like a leap frog. Make an origami leaping frog with directions from a book (like Hector Rojas' Origami Animals) or from this website:
http://www.seagrant.wisc.edu/Frogs/origami_instr.html
Make a frog bank with directions from
www.bluebonnetvillage.com/frogbank.htm
Come into the library and pick up a Frog Maze and a Leap Year Word Search.

Want to find out more about calendars and time? Check out one of these books:
The Story of Clocks and Calendars by Betty Maestro
The Man Who Made Time Travel by Kathryn lasky
Sea Clocks by Louise Borden
Exploring Time by Gillian Chapman
A Second is a Hiccup by Hazel Hutchins
On Time by Gloria Skurzynski