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    Re: Excel Almanac
    From: Bill Ritchie
    Date: 2021 Jan 7, 11:32 +0000
    Hello Sean,

    Since HermanD's  Jan 6, 2021, 4:02 PM  post, I suspect that you have fixed the problem! For Sun, Moon and a few random stars at 2021:1:1 at 00:00:00 all stated values agree with Astron exactly and only minor differences for planets.

    I did notice that small discrepancies appear progressively with past dates for the Moon. (0.4' difference in GHA on 1901:1:1: 00:00:00 from Astron and Frank's Nautical Almanac Data).
    Even more trivial, you state a start date of 1900:1:1 00:00:00. In fact it gives errors before the 19 hours 12 minutes of that millennium!

    Your earlier post of Jul 28, 2020, 5:16 AM states "There are no macros in the workbook - only tables." My official version of Excel flags up 24 of them!

    As the latest UK Covid lockdown bites, I'll make more detailed comments to you directly via the link given in your instructions tab. Hope this helps. 


    Bill Ritchie


    On Wed, Jan 6, 2021 at 4:02 PM Herman Dekker <NoReply_Dekker@fer3.com> wrote:

    Hello Sean,
    I changed only the UT to 00:00:00 (on 1 jan 2021) the calculated Sun GHA is 179°06,9' that's not the same as I get from other sorces.
    On average (10 sources) it is 179°08,5' so what is, or do I wrong?
    I tested this because by conincidence a few days ago  I was on the webstite of Johannes Hornbach. TheNauticalAlmanac.com
    He has a nice collection off Celestial tables etc. and a Forum that nobody seems to use.
    His complete nautical Almanac for 2021 has as GHA value 179° 08,2' I attended him on this (also) wrong value.
    He thought it is the PYEem program that generates the wrong value.
    His only Sun Almanac give the most common 179°08,5' value. Generated with one other program.
    So Sean can you check your GHA value, or inform me how to use the program.

    Kind regards

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