Ok why does the whole leap year thing have to be so d**n complicated?!?

Question

http://en.wikipedia.org/wiki/February_29

why cant they just change the length of time in a second to make up for that extra six hours? no one would really notice since it would only have to be a really small change.

for that matter when the h**l are we gonna go to metric time? one day divided into 10 hours, one hour divided into 10 minutes, one minute divided into 10 seconds. that would be perfect!

Answer 1

There are two "times" involved: The time of day and the time of year.

The time of day is directly related to the time it takes the Earth to  make one rotation. We've divided that into 24 hours, which are sub-divided into 60 minutes/hour and 60 seconds/minute. These are MUCH better numbers that 10 because they're divisible into whole numbers by more numbers than 10 is. 60 is directly divisible by 2, 3, 4, 5, 6, 10 etc. 24 is directly divisible by 2, 3, 4, 6, 8, 10 etc. 10 is only directly divisible by 2 and 5. This leads to fewer "fractional" times that we'd get by using 10.

The time of year is directly related to the time it takes the Earth to make one orbit of the Sun. Ideally we'd like this to be an exact multiple of the day. But it's not. We can't change the length of each day, because the day is always the time for one revolution, our only option is to add an extra day every 4 years to compensate for the fact that it takes slightly more than 365 days to orbit the Sun.

Answer 2

If a second were made just slightly longer so that every day had 24 hours and every year had 365 days, eventually the time on a clock would not quite correspond to the actual time.

It is the same as a clock that moves too slowly.  At first the clock is set correctly.  But as months goes by, the clock falls behind the actual time. The time the sun rises (or any other measure) gets earlier and earlier.  After two years, the clock would be half a day off.  The sun would rise in the pm and set in the am.  After 4 years, the actual time would "lap" the clock and it would appear to be right again, but it will be an entire day off.

As for metric time - too much hassle

Answer 3

Because there is 365 and 1/4 days in a year...if we change it...we would be a day older....time started at the past...we could not change it...if you change it.....time is ruined..you'll get older...blah...blah...

Answer 4

The leap year schedule can't be fixed by adopting a new time system, unless you allow the time system to be unrelated to the position of the Sun in the sky.  I think you'll agree that it is necessary for the timekeeping system to be aligned with the Sun's rising and setting, since the Sun is an important part of daily life.

The reason for the complexty is that the ratio of the time it takes Earth to make one orbit of the Sun (one year), and the time it takes for the same spot on the Earth to face the Sun successively (one solar day) is not a simple number - there are 365.242199 solar days in one year.  This is just how the solar system formed, and there's nothing we can do to change it.

If you choose the year to be 365 days long, you'll be almost one day short after four years.  So we add an extra day every four years, giving us an average of 365.25 days per year.

365 + 1/4 = 365.25

However, this means that after 128 years, you'd have one day too many.  So, every 100 years, we skip a leap year, giving us an average of 365.24 days per year.

365.25 - 1/100 = 365.24

We're getting close, but after 454 years, we'd be short one day with this system.  So, every 400 years, we add a leap year back where we had removed one with the previous step.

365.24 + 1/400 = 365.2425

This brings us to 365.2425 days per year.  With this system, we still gain an extra day every 3,322 years, but we consider it to be sufficiently accurate, and as you say, it's complicated enough already.

As for the metric time, it's never going to happen.  If it did, I would prefer that the seconds be similar in length to our current seconds.  There are about 86,000 seconds in a day, so we could use 100,000 seconds per day in our new time system:  10 hours per day, 100 minutes per hour, and 100 seconds per hour.