sunrise(3)
NAME
Astro::Sunrise - Perl extension for computing the sun
rise/sunset on a given day
SYNOPSIS
use Astro::Sunrise; ($sunrise, $sunset) = sunrise(YYYY,MM,DD,longitude,latitude,Time Zone,DST);
DESCRIPTION
- This module will return the sunrise/sunset for a given
- day.
- Eastern longitude is entered as a positive number
Western longitude is entered as a negative number
Northern latitude is entered as a positive number
Southern latitude is entered as a negative number - There are a number of altitides to chose from, I have
- chosen
-0.833 because this is what most countries use. Feel - free to
change it if you need to. Here is the list:
h = 0 degrees: Center of Sun's disk touches a mathemat - ical horizon
h = -0.25 degrees: Sun's upper limb touches a mathemat - ical horizon
h = -0.583 degrees: Center of Sun's disk touches the - horizon; atmospheric refraction accounted for
h = -0.833 degrees: Sun's supper limb touches the hori - zon; atmospheric refraction accounted for
h = -6 degrees: Civil twilight (one can no longer read - outside without artificial illumination)
h = -12 degrees: Nautical twilight (navigation using a - sea horizon no longer possible)
h = -15 degrees: Amateur astronomical twilight (the sky - is dark enough for most astronomical observations)
h = -18 degrees: Astronomical twilight (the sky is com - pletely dark)
- sunrise
($sunrise, $sunset) = sunrise(YYYY,MM,DD,longi- tude,latitude,Time Zone,DST);
($sunrise, $sunset) = sunrise( 2001, 3, 10, 17.384, - 98.625, -5, 0 );
- Returns the sunrise and sunset times, in HH:MM format.
(Note: Time Zone is the offset from GMT and DST is day
light savings time, 1 means DST is in effect and 0 is not.
AUTHOR
Ron Hill rkhill@pacbell.net
Many thanks also go to Paul Schlyer, Stockholm, Sweden for
his excellent web page on the subject.
CREDITS
- Thanks very much to:
- Rich Bowen (rbowen@rbowen.com) for suggestions
- Adrian Blockley [adrian.blockley@environ.wa.gov.au] for finding a
- bug in the conversion to local time
COPYRIGHT and LICENSE
Here is the copyright information provided by Paul
Schlyer:
Written as DAYLEN.C, 1989-08-16
Modified to SUNRISET.C, 1992-12-01
(c) Paul Schlyter, 1989, 1992
Released to the public domain by Paul Schlyter, December
1992
Permission is hereby granted, free of charge, to any per
son obtaining a copy of this software and associated docu
mentation files (the "Software"), to deal in the Software
without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice
shall be included in all copies or substantial portions of
the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARIS
ING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
USE OR OTHER DEALINGS IN THE SOFTWARE.