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Discussion on: I'm an open source enthusiast at Mapbox, the creator of Leaflet and 40+ other JS libraries, and a rock musician. AMA!

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Zeke Sikelianos

You created the SunCalc library for calculating sun position, sunlight phases (times for sunrise, sunset, dusk, etc.), moon position and lunar phase for the given location and time. How does it work and what are some interesting ways that people have used it over the years?

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Scott Davis

This is a cool use of that project:

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Vladimir Agafonkin Ask Me Anything

The library came out of a website,, which I built more than 8 years ago and pretty much haven't updated since (you can tell by the fact that it still uses Google Maps :) — and I received so many wonderful e-mails about it over the years.

I got letters from imams who used it for optimal prayer times, from a Tibet monk who used it to plan lunches, from air conditioner installers, from people who used it when choosing a home / apartment to buy, and from many enthusiastic gardeners.

But the most endearing e-mail I got related to it is this one, and it warms my heart with joy and happiness:


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Jeff Maynard

I use suncalc to work out Nautical Twilight for my app River Thames Guide (boats and ships registered in the UK should strike their ensign at 2100 or Nautical Twilight whichever is earlier).
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