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

[Michael Sokolov]

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.

MS