Accurate astronomical Wheel of the Year
https://wheeloftheyear.soundragon.su
under DWTWL 2.55 license: https://soundragon.su/license/license.html
Time data from the Institute for Celestial Mechanics and Computation of Ephemerides
Vernal Equinox: https://www.imcce.fr/newsletter/docs/Equinoxe_printemps_1583_2999.pdf
Northern Solstice: https://www.imcce.fr/newsletter/docs/Solstice_ete_1583_2999.pdf
Autumnal Equinox: https://www.imcce.fr/newsletter/docs/Equinoxe_automne_1583_2999.pdf
Southern Solstice: https://www.imcce.fr/newsletter/docs/Solstice_hiver_1583_2999.pdf
Original Octosol image by DougInAMug: https://gitlab.com/DougInAMug/octosol