Shabat times algorithm?

Does someone knows of an open source algorithm for calculating the times of Shabat candle light by a GPS location?

I've found this site: hebcal that have a rest api but it doesn't s开发者_运维问答upport a gps. they directed me here but its not very understandable.

any help will be appreciated.

Thanks.

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The times to light and extinguish Shabbat candles are based on local sunset. So what you really need is a way to compute the sunset time for any location on a particular date.

As I understand it, candles are lighted 18 minutes before local sunset. So once you compute the sunset time, just subtract 18 minutes and you're there.