1 This is used for display only. This will not change the longitude and latitude required for proper zmanim calculation. Please look up proper values for the other fields before generating the calendar.
2 You can use Google Maps to select the latitude and longitude for your location. To use this feature, click on the
icon to display the map. Use the map controls to get to the desired location and click on it. This will set the longitude and latitude for the point on the map that you clicked.
3 Use negative numbers south of the equator.
Note: For far northern (or southern) locations such as England some zmanim during part of the year such as early calculation of
alos in the spring, that by calculation do not occur since the sun never reaches that far below the horizon (and actually calculate to an invalid mathematical value, see JavaDocs of
AstronomicalCalendar for more information) will have a value of N/A.
4 Use negative numbers west of the
prime meridian (Greenwich).
5 Elevation in Meters above sea level. Negative numbers can not be used. This is used by some sunrise / sunset algorithms to adjust times based on elevation Only sunrise and sunset calculations are adjusted as per
Yisroel Vehazmanim and
Calendrical Calcuations. It is currently implemented by all algorithms in the Zmanim package using the formula zenith = zenith + Math.toDegrees(Math.acos(earthRadiusInMeters / (earthRadiusInMeters + elevationMeters))) found in Calendrical Calculations. An almost identical algorthm found in
Maaglay Tzedek would be to add 0.0347 * squareRoot(elevationMeters) to the zenith. Use 0 to default to the standard algorithms.
Note: Elevation lookup courtesy of
Jonathan Stott's earthtools.org elevation webservice. This Elevation data currently only covers the USA and part of Europe. Please see the
About the Data section for the coverage map.
6 Locations such as Israel where the start and end of daylight savings time varies from year to year will have an inaccurate start of daylight savings time. I will hopefully soon change the page to allow entry of optional start and end of daylight savings time.
