We have leap year because there aren't exactly 365 days in a year, so we add an extra day every fourth year. But if you think about it, there aren't exactly 24 extra hours in 4 years either. So even with leap year, we're still slowly becoming off-sync with the earth's...

+208 We have leap year because there aren't exactly 365 days in a year, so we add an extra day every fourth year. But if you think about it, there aren't exactly 24 extra hours in 4 years either. So even with leap year, we're still slowly becoming off-sync with the earth's rotation and orbit. The system we use to keep track of time is not perfect, amirite?

by Anonymous 11 years ago

I don't get it :/ basically a year is pretty much 365 days and 6 hours, and 4 times 6 is 24 hours...

by Anonymous 12 years ago

But it's not EXACTLY 6 hours, so every leap year it gets off-set by a few more minutes

by Anonymous 12 years ago

Yeah so in a few thousand years we'll be about a day behind or something :D

by Anonymous 12 years ago

what what about in 500 years? will midnight be bright?

by Anonymous 11 years ago

If I think about it too much it drives me insane.

by Anonymous 11 years ago

Time is a human invention.

by Anonymous 11 years ago

No it's not - time exists, the ways and methods we use to measure time are human inventions, but if we didn't measure time, it would still exist, we'd still get older. If humans didn't exist the sun wound still set and rise, and animals and plants would still age and die.

by Anonymous 11 years ago

that is why we skip years divisible by 100 but not 400. I believe that there is another exception to those rules but as it is the time lost is very very small, so small that the calendar will probably be destroyed by the time it needs to be readjusted. The problem is that our calender uses two arbitrary and independent time measures (the time for the earth to rotate and the time for it to orbit) and so they do not divide evenly into each other. In fact seconds and hours do not go evenly into a day (there are leap seconds).

by Anonymous 11 years ago

If Saigot's explanation doesn't it for you, CGP Grey does an amazing job. Mainly because he's one of the biggest badasses on Youtube. http://www.youtube.com/watch?v=xX96xng7sAE

by Anonymous 11 years ago

I read somewhere that every 400 years the add a couple more days to make up for this...but I'm probably wrong

by Anonymous 11 years ago

I read something similar as well, I'm trying to Google it, but apparently in Greenwich, or wherever the fuck they keep the absolute world clock, they add an extra X amount of seconds every X years, to account for the fact that a year isn't exactly 365.25 days. Still trying to find the article.

by Anonymous 11 years ago

Found it - http://discovermagazine.com/2009/mar/20-things-you-didn.t-know-about-time The earth's rotation isn't reliable, and a leap second is added every few years.

by Anonymous 11 years ago

Also back in the time of the dinosaurs, a day was 23 hours, that's pretty interesting.

by Anonymous 11 years ago

That's why we have leap seconds.

by Anonymous 11 years ago

The earths orbit is slowly, slowing. So that in several hundred years (I can't remember the exact number) we lose a grand total of 1second from the clock!

by Anonymous 11 years ago