Challenge: Sunrise/Sunset on your forum?

[okhissabigfish]

I have a fishing lake website. Fishing rules state that fishing shall start at sunrise and end at sunset daily. I found this code and would love to place a form that places the data somewhere on forumhome.

This kind of creation is a bit over my head...but, I haven't seen anyone work with date/time/events too much here. Anyone up for the challenge? Hopefully when done the member will be able to read the output on screen at page reload, etc. I've not tested this script.

SunRise/SunSet Code:

<?php

class Astro_Sunrise {

// coordinates to calculate sunrise/sunset for
var $lat = 47.0452; // -90..+90; > 0 is north of the equator
var $lon = 7.2715; // -180..+180; > 0 is east of Greenwich

// date
var $year; // 4 digits, please
var $month;
var $mday; // day of the month
var $tz; // timezone offset in hours, > 0 is east of GMT, < 0 is west
var $yday; // day of the year

var $twilight = array(
'effective' => -.0145439, // sunrise/sunset
'civil' => -.104528, // civil twilight
'nautical' => -.207912, // nautical twilight
'astronomical' => -.309017 // astronomical twilight
);

var $R; // radius used for twilight calculation

var $last_utc; // UNIX timestamp of last calculation

function Astro_Sunrise() {
$this->setTwilight('effective');
}

function setCoords($lat, $lon) {
if ($lat < -90 || $lat > 90 || $lon < -180 || $lon > 180)
return null;
$this->lat = $lat;
$this->lon = $lon;
}

function getCoords() {
return sprintf('%1.4f %s %1.4f %s',
abs($this->lat), $this->lat < 0 ? 'S' : 'N',
abs($this->lon), $this->lon < 0 ? 'W' : 'E'
);
}

function setDate($year, $month, $mday) {
if ($year < 100)
$year += 1900;
if ($year < 1600 || !checkdate($month, $mday, $year))
return null;

$this->year = $year;
$this->month = $month;
$this->mday = $mday;

$daysinmonth = array(0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334);
$this->yday = $daysinmonth[$month - 1] + $mday - 1;
if ($month > 2 && ($year % 4) == 0 && (($year % 100) != 0 || ($year % 400) == 0))
$this->yday++;
}

function getDate() {
return sprintf('%04d-%02d-%02d', $this->year, $this->month, $this->mday);
}

function setTimestamp($time) {
list($this->year, $this->month, $this->mday, $this->yday) =
explode(':', date('Y:n:j:z', $time));
}

function setTimezone($tz=0) {
if ($tz < -13 || $tz > 13)
return null;
$this->tz = $tz;
}

function getTimezone() {
$tz = abs($this->tz);
if ($tz == 0)
return 'UTC';
$hours = intval($tz);
$mins = intval(($tz - $hours) * 60 + 0.5);
return sprintf('%s%02d%02d', $this->tz < 0 ? '-' : '+', $hours, $mins);
}

function setTwilight($type) {
if (!array_key_exists($type, $this->twilight))
return null;
$this->R = $this->twilight[$type];
}


function getSunrise() {
return $this->calcSunrise(true);
}

function getSunset() {
return $this->calcSunrise(false);
}

function getLastSwatchBeat() {
$tm = ($this->last_utc + 3600) % 86400; // MEZ
return sprintf("@%03d", 1000 * $tm / 86400);
}

function calcSunrise($isRise) {

// multiples of pi
$A = 0.5 * M_PI; // Quarter circle
$B = M_PI; // Half circle
$C = 1.5 * M_PI; // 3/4 circle
$D = 2 * M_PI; // Full circle

// convert coordinates and time zone to radians
$E = $this->lat * $B / 180;
$F = $this->lon * $B / 180;
$G = $this->tz * $D / 24;

$J = $isRise ? $A : $C;

$K = $this->yday + ($J - $F) / $D;
$L = $K * .017202 - .0574039; // Solar Mean Anomoly
$M = $L + .0334405 * sin($L); // Solar True Longitude
$M += 4.93289 + 3.49066E-4 * sin(2 * $L);

// Quadrant Determination
$M = norm($M, $D);

if (($M / $A) - intval($M / $A) == 0)
$M += 4.84814E-6;
$P = sin($M) / cos($M); // Solar Right Ascension
$P = atan2(.91746 * $P, 1);

// Quadrant Adjustment
if ($M > $C)
$P += $D;
elseif ($M > $A)
$P += $B;

$Q = .39782 * sin($M); // Solar Declination
$Q /= sqrt(-$Q * $Q + 1);
$Q = atan2($Q, 1);

$S = $this->R - sin($Q) * sin($E);
$S /= cos($Q) * cos($E);

if (abs($S) > 1)
return "(Mitternachtssonne/Dauernacht)";

$S /= sqrt(-$S * $S + 1);
$S = $A - atan2($S, 1);

if ($isRise)
$S = $D - $S;

$T = $S + $P - 0.0172028 * $K - 1.73364; // Local apparent time
$U = $T - $F; // Universal time
$V = $U + $G; // Wall clock time

// Quadrant Determination
$U = norm($U, $D);
$V = norm($V, $D);

// Scale from radians to hours
$U *= 24 / $D;
$V *= 24 / $D;

// Universal time
$hour = intval($U);
$U = ($U - $hour) * 60;
$min = intval($U);
$U = ($U - $min) * 60;
$sec = intval($U);
$this->last_utc = gmmktime($hour, $min, $sec, $this->month, $this->mday, $this->year);

// Local time
$hour = intval($V);
$min = intval(($V - $hour) * 60);

return sprintf('%02d:%02d', $hour, $min);

} // function calcSunrise

} // class Astro_SunTime

function norm($a, $b) { // normalize $a to be in [0, $b)
while ($a < 0)
$a += $b;
while ($a >= $b)
$a -= $b;
return $a;
} // function norm

?>