Are there "CORRECT" dates for the CROSSQUARTER DAYS?


"I'm ok with the dates shown for the Quarter Days (solstices and equinoxes),

but what's the deal with your dates for the CROSSQUARTERS?"


The crossquarter values (XQ) are derived from a precise halving of the whole-time extending between each adjacent equinox and solstice. 


It is understood that there are -other- methods sometimes suggested for deriving the XQ values, such as halving the Sun's apparent range of declination (the range of the Sun's position above or below the celestial equator through the year), or by ancient observational methods like watching the sunrise or sunset's progression along a local horizon, or measuring its elevation at local noon, etc. For XQ values calculated by degrees of the Earth’s progress along its orbital path around the Sun, go to: 

BTW, There should be
no reason for debate over the dates of the actual solstices and equinoxes
those are formally recognized and observable astronomical phenomena. On the other hand, the four familiar* dates only
roughly midway between them commonly referred-to as "crossquarters" are not and have never been part of astronomical calendar-keeping (at least not in the annals of recorded history).
The 4 crossquarters and their "familiar" dates (eve/day's) from the surviving Folk Traditions (SFT):
Imbolc (Feb.1-2), Beltaine (Apr.30-May 1), Lughnasa (July 31-Aug.1), and Samhain (Oct.31-Nov.1)

The names just given for those are the Irish SFT versions.


-          ERIC CANALI

For more information, or a clarification, send your request to the following
electronic mail address: < >.

Editor’s Note: This astronomically-related question was answered by a very experienced amateur
astronomer, who also works as a part-time Tour Guide at the Allegheny Observatory
in Pittsburgh. Allegheny Observatory provides public tours two nights a week from
April through October; pre-registration is necessary, but the tours are free-of-charge.

For many years, Eric G. Canali was Floor Manager for the original Buhl Planetarium
and Institute of Popular Science in Pittsburgh. He also was a long-time member of the
Amateur Astronomers' Association of Pittsburgh and is Founder of the South Hills
Backyard Astronomers.

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