Equinox and Solstice Times

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Equinox and Solstice Times

Karl Palmen

Dear Calendar People

 

I’ve for some time been aware of the Stellafane equinox and solstice calculator

https://stellafane.org/misc/equinox.html which gives equinox and solstice times for any year from 1000 to 3000 with day of week correct from 1583 to 3000.

 

I have found a French IMCCE one at

http://www.imcce.fr/langues/en/grandpublic/temps/saisons.html which gives equinoxes and solstices from -4000 to 2500 without day of week. It does not seem to use the words equinox or solstice, but refers to them as seasons.

 

The two sites differ by 9 or 10 minutes for year 1000 when UTC is selected for Stellafane and by over half an hour when TDT is selected by Stellafane. So I assumed the two sites use a different algorithm for UT. The Stellafane sites is accurate to the minute only for 1950 to 2050.

 

The French site also offers calendar conversion from

http://www.imcce.fr/en/grandpublic/temps/calendriers/concordances.html

 

 

Karl

 

16(11(05

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Re: Equinox and Solstice Times

Tom Peters-6

I think for around 1000 AD the error in DeltaT is less than 10 min., but either site may use an obsolete curve – many have been developed over the past decades, sometimes valid for a limited timeframe, so if abused beyond their limits will give wrong results.

 

That they give differences up to 30 min. in TDT means that one of them is wrong.

 

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Onderwerp: Equinox and Solstice Times

 

Dear Calendar People

 

I’ve for some time been aware of the Stellafane equinox and solstice calculator

https://stellafane.org/misc/equinox.html which gives equinox and solstice times for any year from 1000 to 3000 with day of week correct from 1583 to 3000.

 

I have found a French IMCCE one at

http://www.imcce.fr/langues/en/grandpublic/temps/saisons.html which gives equinoxes and solstices from -4000 to 2500 without day of week. It does not seem to use the words equinox or solstice, but refers to them as seasons.

 

The two sites differ by 9 or 10 minutes for year 1000 when UTC is selected for Stellafane and by over half an hour when TDT is selected by Stellafane. So I assumed the two sites use a different algorithm for UT. The Stellafane sites is accurate to the minute only for 1950 to 2050.

 

The French site also offers calendar conversion from

http://www.imcce.fr/en/grandpublic/temps/calendriers/concordances.html

 

 

Karl

 

16(11(05

 

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