Why Do We Still LEAP?.....

[S8NSSON]

I know the reason for the leap year and leap second and why they are distributed the way the are, etc...

But...

Why don't we just adjust our time keeping devices precisely to the calendar? All we would have to do is make the second a little longer, etc... Then everything would fit.

[KnacK]

The leap second, or added seconds or fraction there of are not a constant.  Typically the addition ( I don't know of any subtractions) are based on changes in planetary orbit which looked at down to the millionth or so decimal place are not consistant.

From http://tf.nist.gov/general/leaps.htm

What is a leap second?

A leap second is a second added to Coordinated Universal Time (UTC) to make it agree with astronomical time to within 0.9 second. UTC is an atomic time scale, based on the performance of atomic clocks. Astronomical time is based on the rate of rotation of the earth. Since atomic clocks are more stable than the rate at which the earth rotates, leap seconds are needed to keep the two time scales in agreement.

The first leap second was added on June 30, 1972. Since then, they have occurred at an average rate of less than one per year. Although it is possible to have a negative leap second (a second removed from UTC), so far, all leap seconds have been positive (an extra second has been added to UTC). Based on what we know about the earth's rotation, it seems unlikely that we will ever have a negative leap second.


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Why do we need leap seconds?

Leap seconds are needed so that users of the astronomical time scale (UT1) can use UTC and know that the difference between the two time scales is never greater than 0.9 seconds. Currently the difference between UT1 and UTC is changing at a rate that requires the addition of less than one leap second per year. When a leap second is necessary, an announcement is made at least several months in advance, and all leap seconds so far have been implemented on either June 30th or December 31st. Here is the current difference between UT1 and UTC and a list of all leap seconds.

[jitspoe]

Because people prefer to work during daylight hours, probably.

[Eiii]

All we would have to do is make the second a little longer, etc... Then everything would fit.

That'd probably take several decades to be put into place. And the system works just fine now, everyone's familiar with it, so why change anything?