[LEAPSECS] The Debate over UTC and Leap Seconds

ashtongj ashtongj at comcast.net
Tue Aug 10 11:32:40 EDT 2010

On 2010-08-10 11:03 AM, Poul-Henning Kamp wrote:

> The much larger body of non-working code, which needs to be fixed

> if we continue the leap-second stunt, is not mentioned once in the

> "Favouring change" column.


If one actually wants to compute legally correct durations given the
starting and ending date and time, written in a legally acceptable
manner, one has a great many programs to fix, and in some countries and
time periods it is impossible to decide the right answer. This is
because many countries legally observe UTC-based time, and the leap
seconds must be counted in the duration. Many countries nominally
observe GMT-based time, but their national time laboratories provide
UTC, so it is hard to decide what the actual legal time standard is in
those countries. These problems will continue to exist even if future
leap seconds are eliminated, because the duration to be calculated may
be in the leap second era, or may have begun in the leap second era.

Fortunately this problem does not come up very often, but there are many
computer functions that purport to do this but really don't.

Gerry Ashton

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