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    Re: Time
    From: Richard B. Emerson
    Date: 2000 Nov 09, 5:08 PM

    "Dave Weilacher"  writes:
     > Anyone got concise definitions of various "time"s
     > and formulas for converting from/to.
     > For example:
     > Zulu time
     > UCT
     > UTC
    They're all the same thing - well, there are different versions of UTC
    but practically speaking it's safe to assume they're the same.  "Zulu"
    is courtesy of the military who assigned a letter to each time zone.
    "Zulu" is the radio phonetic for the letter "Z".  UTC is derived from
    the French for Universal Coordianted Time (UCT is not preferred).  GMT
    (Greenwich Mean Time) is an earlier name for UTC.
     > Zone Time
    The time kept within a given time zone.  For example, Eastern Standard
    Time is 5 hours before UTC.  Currently the zone time here is 1855
    while it's 2355 UTC.
     > Watch time
    Whatever time your watch shows.  If the watch is fast or slow, it is
    not the same as zone time (or UTC, if you set the watch to UTC).
    Watch time is subject to all the errors inherent in any time keeping
    device and these errors must be taken into account when reducing a
     > Ship's time
    The same thing as watch time although it's possible the ship's clock
    might keep other than zone time (e.g., UTC) to clear up problems with
    changing time zones.
     > etc.
    Et cetera - it's Latin and can be translated as "and others" [of the
    same kind].  [g]
     > How about local apparent noon
     > Meridian passage of sun
     > ....
    Quoting Bowditch, "Twelve o'clock local apparent time, or the instant
    the apparent sun is over the upper branch of the local meridian.
    ... Sometimes called High Noon".
    Apparent time, in term, is tied to the actual position and the
    meridian associated with that position as opposed to zone time (where
    all clocks show the same time, regardless of the longitude of the
    S/V One With The Wind, Baba 35

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