Thank you so much.

I am a pilot and need twilight info for operational purposes everyday. I use to get it from a calculator on the weather network but they since removed it from their website and left me in a scramble to find a new method and SunCalc is a god send, way better than anything I've ever used. I can even find twilight times for remote locations that I fly to. Extremely handy, I was never able to do this before. You don't know how happy I am right now.

Regarding improvements. I am not sure. Just found the site today. Just had to thank you.