[LEAPSECS] Lets get REAL about time.

[Keith Winstein]

On Mon, Jan 23, 2012 at 12:18 PM, Rob Seaman <seaman at noao.edu> wrote:


> Whatever the design parameters of new APIs, e.g., floating-point or not, they will only succeed if the underlying conceptual model resembles the real-world.  Steve Allen's concept of how such interfaces should interact with the system of timezones:

>

>        http://www.cacr.caltech.edu/futureofutc/preprints/45_AAS_11-681_Allen.pdf

>

> is 1) written down and has references, and is 2) conformant with the real-world.  On the other hand, the timezone assumptions underlying the "Draft Revision to ITU-R Recommendation TF.460-6" are neither.  We need to revise the revision.


It's a good proposal, but I think the principal disagreement lies in
their choice of how to handle as-yet-unannounced intercalary seconds.

Steve Allen has opted for my #2 ("Correctly account for past leap
seconds, and ignore yet-to-be-disseminated future leap seconds when
converting EST/EDT/UTC-specified moments into a timestamp").

PHK has chosen #3 ("Correctly account for past leap seconds, and bomb
out with an error when converting future EST/EDT/UTC-specified
moments").

I think it's useful to make that disagreement explicit. I don't think
either choice #2 or #3 is more "conformant with the real world" than
the other.

Of course Steve's is nice because it doesn't require modifying
existing applications.

-Keith