On: Look Before You Leap – The Coming Leap Second and ...

[bjackman]

What are the advantages of the curved one? I've never worked on an application that would care about this kind of thing, so I'm struggling to imagine the implications.

[TheLoneWolfling → bjackman]

Suppose you have something with a watchdog that times something every time it runs to check that nothing suddenly gets slower / faster. A backup or something.

Let's suppose that the amount of time it takes to run is relatively small. Now suppose between two runs the linear decrease starts. All of a sudden the second run appears to be slower than it is by a constant factor.

With a curved change, this effect still happens, but it's less for smaller time intervals.

[acqq → TheLoneWolfling]

The shortest explanation would be that the curve can be introduced to lower the average difference between the official time and the adjusted time.

bjackman "never worked on an application that would care about this kind of thing," fine, but for those that do care, the curve is obviously better.

[TheLoneWolfling → acqq]

Another way to look at it: the curve keeps the second derivative of time bounded. Which in turn keeps anything analogous to acceleration bounded.

[acqq → TheLoneWolfling]

Good point, thanks! Here's the example picture of the curve:

http://i.imgur.com/oYboqSL.png

[tarpherder → bjackman]

I'm guessing some applications may be sensitive to a sudden change in second duration and they probably argued that a gradual introduction of change would trip up the least amount of programs.