Time for a very geeky post...

Recently, on the remind (diary tool I used to use) mailing list,
somebody posted a script for converting solar data (perihelion, equinox,
...) to remind input.  I've done the same for org so if you're
interested in that kind of information and want your agenda to show
this, here is the script:

#+begin_src shell :results output raw
  tmpfile=$(mktemp /tmp/date.XXXXXX)
  for year in $(seq 2018 2068)
  do
      links http://aa.usno.navy.mil/seasons?year=${year} -dump | \
          grep -E 'helion|quinox|olstice' > ${tmpfile}
      while read -r line
      do
          item=$(echo $line | awk '{print $1}')
          date="$(echo $line | awk '{print $5 " " $4 " " $3}') ${year}"
          isodate=$(date --date="${date}" +"%Y-%m-%d %H:%M")
          echo "** <${isodate}> $item"
      done < ${tmpfile}
  done
  rm ${tmpfile}
#+end_src

Notes:

1. this is for Linux and assumes bash as the shell.
2. the default is UTC (and this is where I wish org supported time
   zones...).
3. I believe the URL for the US Naval Observatory in the code above
   accepts "?tz=N?dst=M" for different time zones (some index N) and
   daylight savings options (M set to 0 or 1 maybe?) but I haven't
   played with these options.
4. you will need to install "links".

Enjoy but use at own risk etc. ;-)

--
Eric S Fraga via Emacs 27.0.50, Org release_9.1.11-620-ga548e4