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    Re: half-hour time zones
    From: Brian Whatcott
    Date: 2001 Nov 03, 4:34 AM

    At 06:44 PM 11/2/01 -0800, you wrote:
    >Anyone know why some places have time offsets not an integral number
    >of hours from Greenwich? Like Newfoundland.
    
    ///
    
    >paulhirose---.net (Paul Hirose)
    
    
    Once upon a time, people used a natural means of setting a time reference,
    by inspection of the Sun's meridian crossing (though they might prefer to
    postpone their lunch break to a few hours later, at the hottest time of day,
    once called 'noon').
    
    Then the railroad engine was developed in a compact country where holding a
    common time standard was no inconvenience. It soon spread to Russia and
      USA where the Sun takes several hours to transit. For railroad schedulers,
    this was a nightmare - and wasn't much fun for continental travellers.
    
    Greenwich competed successfully with Paris Mean Time as a time standard for
    marine navigators, and so some means of indexing time zones from Greenwich
    was hit on as a means of bringing order to the railroad schedule.
    
      The trick was to draw lines on the map which avoided large conurbations,
    as far
    as possible. Having neighbors in a town operating at one hour offsets would
    not
    be a pleasant sight. And so an Eastern, Central, Mountain, and Pacific time
    zone
    was decided, which worked well in general - though in particular, there
    were difficulties.
    
    To mention just two: near Chicago, where there were several towns near a
    boundary,
    another east of Eastern time zone where there was not enough territory for the
      'center of gravity' for the territory to be one hour earlier. They chose
    a half hour
    decrement to keep the local noon (modern sense) near the clock noon.
    
    [I have slightly dramatized this story, hopefully without blurring the
    messy truth
    excessively]
    
    Brian W
    

       
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