Re: Predictable Internet Time

[Joe Touch <[e-mail]>]

On 1/3/2017 12:34 PM, Tony Finch wrote:
>
> Joe Touch <[e-mail]> wrote:
> > We really need to separate the frames of reference of time - there's no
> > need for smear for internal "seconds since epoch" time.
>
> Well, the problem is that "seconds since the epoch" is not a count of
> UTC seconds,

Correct; it's UTC-(leap seconds since epoch start).

> it is a mapping from broken-down time to a linear time,

Seconds since epoch is as linear as it gets.

> and the mapping is defined in a way that requires 86400 seconds per
> day and does not accommodate leap seconds.

The conversion of epoch seconds to larger units is where the leap
seconds is counted.

A "day" as a unit of time is not exactly 86400 seconds (if it were, we
wouldn't need leap seconds).

> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16
>
> Leap smear exists mainly because "seconds since the epoch" does not
> allow for leap seconds.

Seconds since epoch is unambiguous and linear.

It is in the conversion to other representations or aggregations where
leap seconds needs to be considered.

Joe