[scrumper]

It's great. The 12, 24, and light clock visualization is particularly good.

In terms of feedback, only one thing: The first thing I tried didn't work. This was dragging the map so I could explore the effect of latitude on day length in both hemispheres. It appears to only support the case where the crosshairs are near an actual city (which is not possible deep down in the southern hemisphere).

[Zikes]

This might benefit from the code at https://bl.ocks.org/mbostock/4597134, which uses lat/long directly.

[dassreis]

I like that. Big fan of D3