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Old April 20th 18, 09:26 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Averaging and the Equation of Time

I wish there were people with some discipline who recognized that noon is a fixed event defined by the position of the observer to sunrise when their location turns through the circle of illumination and sunset when the observers turns back through the circle of illumination.

The anchoring of rotation to the noon cycle exposes the flaw in Huygen's reasoning that the Equation of Time is outside the calendar framework -

Here take notice, that the Sun or the Earth passeth the 12. Signes,
or makes an entire revolution in the Ecliptick in 365 days, 5 hours 49
min. or there about, and that those days, reckon'd from noon to noon,
are of different lenghts; as is known to all that are vers'd in
Astronomy. Now between the longest and the shortest of those days, a
day may be taken of such a length, as 365 such days, 5. hours &c. (the
same numbers as before) make up, or are equall to that revolution: And
this is call'd the Equal or Mean day, according to which the Watches
are to be set; and therefore the Hour or Minute shew'd by the Watches,
though they be perfectly Iust and equal, must needs differ almost
continually from those that are shew'd by the Sun, or are reckon'd
according to its Motion. But this Difference is regular, and is
otherwise call'd the Aequation.." Huygens

The averaging process is the sum of all total lengths divided equally creates the 24 hour average including the rotation that is now February 29th. Men are supposed to recognize that while one 24 hour day correlates to one rotation, a year does not correspond to one orbital circuit of the Earth so from March 1st to February 29th for one yearly cycle is just as valid as from March 1st to February 28th. Timekeeping comes into close proximity to planetary dynamics but that is the reasonable conclusion that has yet to be accepted.