[Remind-Fans] Chinese lunisolar calendar

[Tim Chase]

On 2023-12-29 10:14, Remind list wrote:
> On Fri, 29 Dec 2023 09:19:13 +0900
> taekoocair--- via Remind-fans <remind-fans at lists.skoll.ca> wrote:
> 
> > Is there any reasonable way to encode the Chinese solar terms?
> 
> I would say not really in the Remind language itself.  The code Tim
> Chase posted might be somewhat accurate (I have not tested it) but I
> doubt it conforms to the official specifications.  The Earth's orbit
> is elliptical, and I'm sure that messes with the calculations, though
> probably not much as the eccentricity of the orbit is pretty low.

Yeah, the eccentricity may have been what squished my dates off by
a day or two in either direction.  My test was to

  REM MSG Solar term: [$T] [angle_to_st($T)]

item and then

  $ rem \*365 | sed '/Reminders for/d' | less

and eyeball the transition dates compared to the Wikipedia table
where they were all largely within a day of accurate.

-tim