Re: [Tzdist] shepherd review and issues for draft-ietf-tzdist-caldav-timezone-ref

[Steve Allen <[e-mail]>]

On Thu 2015-06-11T12:16:50 -0400, Cyrus Daboo hath writ:
> --On June 11, 2015 at 9:12:40 AM -0700 Steve Allen <[e-mail]> wrote:
>
> >I think this situation will happen indefinitely.  The Lick Observatory
> >telescope schedules have always operated in a time zone where the new
> >day begins at noon PST, or 20 hours behind Greenwich.  This will never
> >be a standard timezone, but the de facto practice is unlikely to change.
>
> As a matter of interest, do you know the reasoning behind that choice?

sic semper faciebamus.  I think the reasoning is unlikely to be
written explicitly.  It is a conventional local shorthand notation for
a telescope schedule where the inspiration belongs with John
Herschel's 1849 "Outlines of Astronomy" page 678

https://books.google.com/books?id=uj0DAAAAQAAJ&pg=PA678&hl=en#v=onepage&q&f=false

Herschel adopted Scaliger's Julian period with days starting at noon
in Alexandria.  For international purposes that later got moved to
noon at Greenwich.  As things have become robotic over the internet
the convention persists in that the authentication tokens for the use
of a telescope expire at noon.

--
Steve Allen                 <[e-mail]>               WGS-84 (GPS)
UCO/Lick Observatory--ISB   Natural Sciences II, Room 165   Lat  +36.99855
1156 High Street            Voice: [phone]          Lng -122.06015
Santa Cruz, CA 95064        http://www.ucolick.org/~sla/    Hgt +250 m