Calculate Sunrise and Sunset v.05

	year	month	day
Date:
	deg	min
Latitude:
	deg	min
Longitude:

Result

Times given in UTC

Sunrise	h.m	Sunset	h.m
Azimuth	deg	Azimuth	deg

Dawn ~

±5 min

Description

This program calculates the times of sunrise and sunset in terms of UTC (=Universal Time Coordinated). Times are displayed e.g. as "17.32 h.m" = 17 hours and 32 minutes. UTC corresponds to winter-time in London. For time-zone Berlin add 1 hour, add 2 hours in summer. For New York subtract 5 hours, in summer 4 hours. The precision of the times for sunrise and sunset is about 1 minute, for duration of dawn 5 min. At positions beyond 60 degrees latitude precision of dawn decreases. Longitude is positive for East, negative for West. Latitude is positive for North, negative for South.

Results were checked against Nautisches Jahrbuch 2020 by Bundesamt für Seeschifffahrt und Hydrographie and against the NOAA Solar Calculator https://gml.noaa.gov/grad/solcalc/. An explicit program can be found at https://gist.github.com/Alex1Git/8616956 where reference is made to Roland Brodbeck. The formulas have been checked with https://www.astronomie.info/zeitgleichung/neu.html. See also the book Astronomical Algorithms by Jean Meeus.

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LICENSE

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License 3. Use it at your own risk, no liablility accepted. We give no guarantee whatsoever.   − H. Müller-Krumbhaar

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last update 4. may 2023