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Answered

Zmanim calculation with elevation

davidamiga14 11 months ago updated by Michael J. Radwin 11 months ago 1

Hi

I'm using this API https://www.npmjs.com/package/@hebcal/core

I want to know if there is a way to add elevation in addition to lat, long coordinates for zmanim calculation

Thanks

Answer

+1
Answer
Answered

Hi, thanks for using the Hebcal JavaScript library. 


Zmanim, Candle-lighting and Havdalah times are derived from sunset times, which are approximated from a location (latitude, longitude) and day of year. There is no way to include elevation in the Hebcal zmanim calculations because the underlying solar calculation algorithm doesn't use elevation.

The NOAA solar algorithm claims accuracy within 2 minutes except at extreme northern or southern latitudes. Adding elevation often changes the sunset calculation by 1 minute or less, so this is within the expected margin of error.

+1
Answer
Answered

Hi, thanks for using the Hebcal JavaScript library. 


Zmanim, Candle-lighting and Havdalah times are derived from sunset times, which are approximated from a location (latitude, longitude) and day of year. There is no way to include elevation in the Hebcal zmanim calculations because the underlying solar calculation algorithm doesn't use elevation.

The NOAA solar algorithm claims accuracy within 2 minutes except at extreme northern or southern latitudes. Adding elevation often changes the sunset calculation by 1 minute or less, so this is within the expected margin of error.