day length calculations

amanda braley braley at
Fri Sep 8 10:14:53 EST 1995

Does anybody know of or have a basic (or similar) computer model that
will calculate the hours of daylight at any given latitude? I'm 
working on a photoperiod project for which knowing the weekly 
average hours of daylight at the various latitudes from which the 
stock plants were collected would be usefull.  I have a table of 
sunrise and sunset times, from which I could painstakingly calculate 
the hours of daylight myself, but I was hoping somebody might have been
clever enough to write a little model to do this for me.


Amanda Braley
Staff Research Associate
University of California
Riverside, CA 92521
braley at

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