Wednesday, February 29, 2012

Some Leap Year Trivia

Then God said, "Let there be lights in the expanse of the heavens to separate the day from the night, and let them be for signs and for seasons and for days and years;” Genesis 1:14

2012 is a leap year, which means that it has 366 days instead of the usual 365 days that an ordinary year has.  An extra day is added in a leap year—February 29 —which is called an intercalary day or a leap day.  Why is a Leap Year Necessary?

Leap years are added to the calendar to keep it working properly.  The 365 days of the annual calendar are meant to match up with the solar year.  A solar year is the time it takes the Earth to complete its orbit around the Sun — about one year.  But the actual time it takes for the Earth to travel around the Sun is in fact a little longer than that.  (365 days, 5 hours, 48 minutes, and 46 seconds, to be precise).  So the calendar and the solar year don't completely match—the calendar year is a touch shorter than the solar year.
It may not seem like much of a difference, but after a few years those extra quarter days in the solar year begin to add up.  After four years, for example, the four extra quarter days would make the calendar fall behind the solar year by about a day.  Over the course of a century, the difference between the solar year and the calendar year would become 25 days!  Instead of summer beginning in June, for example, it wouldn't start until nearly a month later, in July.  So every four years a leap day is added to the calendar to allow it to catch up to the solar year.

But Wait! It's Not Quite that Simple!  The math seems to work out beautifully when you add an extra day to the calendar every four years to compensate for the extra quarter of a day in the solar year.  The exact length of a solar year is actually 11 minutes and 14 seconds less than 365 ¼ days.  That means that even if you add a leap day every four years, the calendar would still overshoot the solar year by 11 minutes and 14 seconds per year.  So, after 128 years, the calendar would gain an entire extra day.  It seems the leap year rule, "add a leap year every four years" was a good rule, but not good enough!

To rectify the situation, the creators of our calendar decided to omit leap years three times every four hundred years shortening the calendar every so often and ridding it of the annual excess of 11 minutes and 14 seconds.  So in addition to the rule that a leap year occurs every four years, a new rule was added: a century year is not a leap year unless it is evenly divisible by 400. This rule manages to eliminate three leap years every few hundred years.  Now the calendar year and the solar year are just about a half a minute off.  At that rate, it takes 3,300 years for the calendar year and solar year to diverge by a day.

Amazing how little things can add up to a lot.  A few minutes here and a few seconds there and the whole calendar is changed! 

Life carries the same principle.  It seems there are no big things...just little things that add up to become a big thing.  So much of life is spent adding on to the things of yesterday that sometimes we don’t realize how big something has become.  Things like: how long it has been since you called a friend, how many times you have cheated on your diet or how far you have gotten behind on your work.  It’s a shame there isn’t a way to call for an adjustment to our lives to reclaim the lost time and failed opportunities.  Looks like the only option is to pay attention to the little stuff because it sure adds up in a hurry.

Statement to Claim:
"His master said to him, 'Well done, good and faithful slave. You were faithful with a few things, I will put you in charge of many things; enter into the joy of your master.' Matthew 25:21

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