Maybe this is the stupidest question I ever asked. But if Leap Day comes every four years, making that year one day longer than other years, how does the summer and winter solstice manage to fall on exactly the same date every year?
See, I'm not even sure the question is intelligent enough to be understandable.
Yesterday, at the coffeeshop, Ander kept going up to Zoe and saying, "Baby. It cute." He he.
Etcetera.
the equinoxes and solstices are not always on the same day. http://aa.usno.navy.mil/data/docs/EarthSeasons.php
ReplyDeleteSpring 20 or 21
Summer 20 or 21
Fall 22 or 23
Winter 21 or 22
My thought is that the purpose of the leap year is actually to keep the calendar basically in sync with nature. So if we didn't have leap year, the solstices would gradually drift further and further back in the calendar. I think it's back. I'm not good with the direction part of it.
ReplyDeleteAll I know about a leap year is that us "salary" employees give our bosses a whole extra day of FREE work. Yes, I'm disgruntled about the whole thing....haha
ReplyDeleteThe earth's orbit around the sun is actually ~365.25 days, NOT 365 days. So, the purpose of the leap year is to reset the calendar to the earth's orbit. Otherwise, the solstices would drift and the seasons would not occur at the "normal" time of the calendar. Imagine Christmas in the dead of summer....
ReplyDeleteI feel sorry for the poor saps whose birthdays occur on 2/29... They only get one birthday every 4 years.
Robert
OK, here's the thing - a year is actually a little over 365.25 days long, so it's not just that it's divisible by 4. The rule is that if it is divisible by 4, it is a leap year except if it is also divisible by 100, unless that number is also divisible by 400. Computer science people have to deal with this craziness all the time - the year 2000 was a leap year because, despite the fact that it is divisible by 100, it is also divisible by 400. 2100, however, will not be a leap year, despite being divisible by 4 because it is divisible by 100 and not by 400. Then every once in a while they will throw in a leap second. Fortunately, nowadays most computers run a synchonization service with one of the atomic clocks to stay synchonized, but we still have to calculate future dates for scheduling purposes. And if you're born on February 29, at least you get to get the free kidies meal for a while, but it must suck to reach retirement age. Of course, all of this is based on the Gregorian calendar. In fact, there was a period of time when most of the countries converted from the Julian calendar (just a straight up 365 days) to the Gregorian calendar and 10 days were eliminated at that time. Some countries, such as Rusia, stuck with the Julian calendar for quite some time, which is why the October Revolution actually occurred in November (according to their calendars, it was in October). Further complicating things is the fact that the gravitational pull of the moon is slowing down the earth's rotation, causing each day to be slightly longer, but the amount of time it takes to orbit the sun remains relatively uniform.
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