How Cumulus calculate sunrise and sunset

[nikokara]

Hallo

May i ask the method Cumulus App calculate's sunrise and sunset, and the method for difference between today and tomorrow daylight.

Note. I'm familar with Delphi (Pascal)

[steve]

It uses a third party component, which uses the same algorithms which I guess most software uses, from the book "Astronomical Algorithms" by Jean Meeus. "Daylight" is the period between dawn and dusk, i.e between the start of morning civil twilight and the end of evening civil twilight.

[Solorize]

After a quick look I have found some examples, see below links
which may help.

Algorithm
http://williams.best.vwh.net/sunrise_su ... orithm.htm

Coded in C
http://souptonuts.sourceforge.net/code/sunrise.c.html

[nikokara]

Thank you Steve, thank you Solorize

U.S. National Oceanic & Atmospheric Administration (NOAA) uses the same algorithm, based on equations from Astronomical Algorithms, by Jean Meeus.

Here are the links
http://www.esrl.noaa.gov/gmd/grad/solcalc/
http://www.esrl.noaa.gov/gmd/grad/solcalc/sunrise.html

PHP has a build in function (date_sun_info) for Sunrise, Sunset, plus Civilian Twilight, Nautical Twilight and Astronomical Twilight.

attached two helpful excel files for Solar Calculations Enjoy!!!

NOAA_Solar_Calculations_day.xls

NOAA_Solar_Calculations_year.xls

[mcrossley]

thank you Solorize

If ever there was a more apt username...

[Solorize]