[LEAPSECS] "China move could call time on GMT"

Michael Sokolov msokolov at ivan.Harhan.ORG
Thu Jan 5 01:39:48 EST 2012

Daniel R. Tobias <dan at tobias.name> wrote:

> World time zone maps generally show a series of perfectly regular

> time zones divided at the appropriate meridians through the oceans

> wherever there aren't any nations that set their time otherwise for

> political reasons.

Yup, and these "ocean time zones" are defined apolitically as mean
solar time at meridians of longitude equal to integral multiples of
15 degrees. Integral hour offsets from a redefined "UTC" would NOT be
an acceptable realization of "civil time at sea" because they would
correspond to MST not at the well-defined N*15 deg meridians, but at
some other set of meridians wandering around the globe.

> However, I suppose on any particular ship it would be up to the

> captain to decide when to adjust ship time, not necessarily exactly

> when those meridians are crossed.

So I guess I should say that integral hour offsets from the ITU2012
form of "UTC" would not be an acceptable realization of "civil time at
sea" on *my* ship. :-) Integral hour offsets from UTR generated by
one of my rubber duckies would have to be used instead.


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