[LEAPSECS] Looking-glass, through

Warner Losh imp at bsdimp.com
Wed Jan 12 18:31:47 EST 2011

On 01/12/2011 13:48, Clive D.W. Feather wrote:

> Rob Seaman said:

>> For instance, what authority will historians or lawyers consult to learn the applicable timezone offsets that were in force in some location(s) during some epoch(s) in question?

> <FX: falls about laughing>


> Those of us on the timezone list can't even find out this information for

> this year for many places. It's almost impossible to determine it for (say)

> 200 years ago for almost anywhere.

That wasn't standardized until the 1850's in the US with the advent of
railroads. Good luck determining it from extant historical records.
The Timezone database is about as good as it gets, and it is horrible
for anything prior to 1990 (no offense guys) if you want more than a
vague idea of something that might be right. It won't tell you that
Chaffee County Kansas moved from the Central Time Zone to the Mountain
Time Zone in 1963, but might tell you if it did in 1983. Just read
through it for different city entries, especially those in Europe that
have changed hands many times this century...

Or lookup February 30th on wikipedia sometime for how there once was a
double leap year in Sweden to get them aligned with the new Gregorian

Time keeping, and even calendar keeping, in the past was a huge
hodge-podge of gunk that only got straightened out most places in the
20th century.

> This is *nothing* to do with what the underlying time scale is. Tony has it

> right: you have things completely backwards.

Agreed. Civil time is de-facto based on what is convenient. Laws were
meant to codify the time products that were available at the time they
were enacted, not enshrine some bizarre way of doing things. The US has
been de-facto UTC since the 1970's, even though the law didn't catch up
with the facts on the ground until just a couple of years ago.


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