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    Re: "Sun Slow Day" is coming...
    From: Hewitt Schlereth
    Date: 2009 Feb 10, 22:01 -0400

    David Burch points out in Emergency Navigation that on Valentine's Day
    the sun is LATE to the meridian. Those of us who have ever been LATE
    with Valentines won't forget it. :-)
    
    Hewitt
    
    On 2/10/09, frankreed@historicalatlas.com  wrote:
    >
    >  Nicolas, you wrote:
    >  "I knew these reactions were coming and to be honest: I would not even
    >  trust the first digit, as I never tested the formula's I found to this
    >  level and neither were they properly annotated. The reason that I gave
    >  so many digits was the simple fact that even to change that last digit
    >  takes almost 15 minutes."
    >
    >
    > Just so you know, I wasn't being facetious when I asked how much we could 
    trust the digits. I'm just curious to see what results other people have had. 
    I tried it myself by two sets of data today. In both cases, I tabulated 
    GMT-GHASun and then fit a parabola to the curve for 48-72 hours around 
    today's date. For the minimum value, I get 14m 13.8s which agrees with yours, 
    as I would expect, but the time of the minimum is near 0230 GMT on February 
    11 which is about an hour and twenty minutes from now as I type this message. 
    And that's about three hours earlier than your minimum. Getting the time of 
    the minimum is of course very difficult since, just as you say, the value is 
    arguably constant (indistinguishable from observations) for a few hours.
    >
    >  Anyway, Happy Sun Slow Day! I have already done my celebratory fourteen 
    minutes and fourteen seconds of procrastination for the day... several times 
    over.
    >
    >  I have a real personal reason for discussing this at length. For the past 
    thirty years, since I first read about the Equation of Time, I have never 
    managed to remember which way the signs go when I need it in practice. 
    Inevitably, I always find myself double-checking. But knowing that February 
    11 is "Sun Slow Day" fixes all of the signs. With any luck, this discussion 
    will keep it in my memory for good. :-)
    >
    >  -FER
    >
    >
    >
    >
    >  >
    >
    
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