It reminds me of this nice website for when you want to have a drink in the sun at a terrasse in Paris :D https://jveuxdusoleil.fr/#16/48.8551/2.3479

Does this handle eclipses

This is great. I would love a way to simulate something like possible tree placement and how much shade that may generate over the years. There are some parts of my area that are, despite being cut out of a forest, devoid of trees but are supposed to be "outdoor shared spaces".

Full sun all day at a dog park in August, for example, just isn't a place I want to be.

Be sure to check out the different layers. In addition to the default which shows shade at a given moment, there are also options for hours of sun in given day, and an a UI to quickly show shade at any day/time of year.