For various reasons (please specify in the solution) the date varies from year to year, but (good news!) it is fully predictable.

Please describe how to find the dates of Solstices and Equinoxes in this century and for that matter for any year, but list them for this century, to allow comparison to published lists, specifying the name and location of your choice, Northern or Southern Hemisphere and the Time Zone.

Default: Paris, France.