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    Re: ZT vs LMT.
    From: Chuck Taylor
    Date: 2000 Dec 07, 11:32 EST

    Dave W wrote:
    > Is it appropriate to use Local Mean Time as being
    > synonymus with Zone Time?
    > My notion of LMT is the time when some event is
    > going to occur at the prime meridian.  The
    > presumption being that this event will then occur
    > at every other meridian.
    That is essentially true for specific cases, such as the time of
    meridian passage or the time of sunrise/sunset.
    > or
    > LMT corrected for longitude (ARC to time) yields
    > GMT.
    Yes.  Also, LMT corrected for the difference in longitude between
    your meridian and the zone meridian (even multiple of 15 degrees
    of longitude) yields ZT (and vice versa).
    >  GMT corrected for zone description (+ or -)
    > gives ZT.
    > If you take a test that says "At 1945 hours,
    > after passing Catalina Island and establishing an
    > evening star fix..."
    > then
    > The next statement reads "All times on this test
    > are either LMT or UT"
    > What kind of time would you take 1945 hours to be?
    I would take it to mean ZT, irrespective of the next
    statement.  I think the person who wrote the test goofed.
    Usually the only time you care about LMT is when computing
    the time of meridian passage or the time of a solar event
    such as sunrise/sunset/twilight.
    Chuck Taylor
    Everett, WA, USA

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