PHP: date_sunrise

Description

mixed date_sunrise ( int timestamp [, int format [, float latitude [, float longitude [, float zenith [, float gmt_offset]]]]] )

date_sunrise() returns the sunrise time for a given day (specified as a timestamp) and location. The latitude, longitude and zenith parameters default to the date.default_latitude, date.default_longitude and date.sunrise_zenith configuration options, respectively.

The latitude defaults to North. So, if you want to specify a South value, you must pass a negative value. The same note applies to longitude, which defaults to East.

The gmt_offset parameter is specified in hours.

Таблица 1. format constants

constant	description	example
SUNFUNCS_RET_STRING	returns the result as string	16:46
SUNFUNCS_RET_DOUBLE	returns the result as float	16.78243132
SUNFUNCS_RET_TIMESTAMP	returns the result as integer (timestamp)	1095034606

Пример 1. date_sunrise() example

<?php /* calculate the sunrise time for Lisbon, Portugal Latitude: 38.4 North Longitude: 9 West Zenith ~= 90 offset: +1 GMT */ echo date("D M d Y"). ', sunrise time : ' .date_sunrise(time(), SUNFUNCS_RET_STRING, 38.4, -9, 90, 1); ?>
Результатом выполнения данного примера будет что-то подобное:
Mon Dec 20 2004, sunrise time : 08:54

See also date_sunset().

date_sunrise

php at stock-consulting dot com
27-Mar-2005 04:22


The function of jbr (AT) ya-right.com will run into an infinite loop for dates/locations without, for example, astronomical twilight (it never gets dark enough for astronomical twilight during June in Cologne, for exmple). Below a quick fix:

<?

function sun_times($time, $lat, $lon, $offset, $format, $dst) {

   $offset += $dst;

   $offset = $offset == 13 ? -11 : $offset;

   $math = array(1.5708, 4.71239, 3.14159, 6.28319, (0.0174533 * $lat), (0.0174533 * $lon), (0.261799  * $offset));

   $data = array('astronomical' => -.309017, 'nautical' => -.207912, 'civil' => -.104528, 'sun' => -.0145439);

   $sd = explode(' ', date('n j Y z', $time));

   $times = array();



   foreach ($data as $a => $b)    {

       for ($x = 0; $x <= 1; $x++) {

           $e = $sd[3] + (($math[$x] - $math[5]) / $math[3]);

           $f = ($e * .017202) - .0574039;

           $g = $f + .0334405 * sin($f);

           $g +=  4.93289 + (3.49066E-04) * sin(2 * $f);

           while ($g < 0) {

               $g += $math[3];

           }

           while ($g >= $math[3]) {

               $g -= $math[3];

           }

           $g += ($g / $math[0]) - intval($g / $math[0]) == 0 ? 4.84814E-06 : 0;

           $h = sin($g) / cos($g);

           $h = atan2(.91746 * $h, 1);

           $h += $g > $math[1] ? $math[3] : ($g > $math[0] ? $math[2] : 0);

           $i = .39782 * sin($g);

           $i = $i / sqrt (-$i * $i + 1);

           $i = atan2($i, 1);

           $j = $b - (sin($i) * sin($math[4]));

           $j = $j / (cos($i) * cos($math[4]));

           $j = $j / sqrt(-$j * $j + 1);

           $j = $math[0] - atan2($j, 1);

           if (!$x) {

               $j = $math[3] - $j;

           }

           $k = $j + $h - 0.0172028 * $e - 1.73364;

           $l = $k - $math[5];

           $n = $l + $math[6];

// Changes begin here

           $key = ($a != 'sun' ? ($x ? 'end' : 'start') : ($x ? $a . 'set' : $a . 'rise'));

           if (is_nan($n)) {

               $times[$a][$key] = '-';

            } else {

               while ($n < 0) {

                   $n += $math[3];

               }

               while ($n >= $math[3]) {

                   $n -= $math[3];

               }

               $n = $n * 3.81972;

               $hour = intval($n);

               $mins = intval((($n - $hour) * 60) + 0.5);

               $times[$a][$key] = date($format, mktime($hour, $mins, 0, $sd[0], $sd[1], $sd[2]));

           }

// Changes end here

       }

   }

   return($times);

}

?>

djwice at [the same] dot com
02-Dec-2004 01:41


The way to use this:



<?php



// De Bilt, The Netherlands, weather station #06260

$lat = 52.10;    // North

$long = 5.18;    // East

$offset = 1;    // difference between GMT and local time in hours



$zenith=90+50/60;

echo "<br><p>Sunrise: ".date_sunrise(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);

echo "<br>Sunset: ".date_sunset(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);



$zenith=96;

echo "<br><p>Civilian Twilight start: ".date_sunrise(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);

echo "<br>Civilian Twilight end: ".date_sunset(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);



$zenith=102;

echo "<br><p>Nautical Twilight start: ".date_sunrise(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);

echo "<br>Nautical Twilight end: ".date_sunset(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);



$zenith=108;

echo "<br><p>Astronomical Twilight start: ".date_sunrise(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);

echo "<br>Astronomical Twilight end: ".date_sunset(time(), SUNFUNCS_RET_STRING, $lat, $long, $zenith, $offset);



?> 



Zenith according to the U.S. Navy's 1990 Almanac for Computers.



Thanks to George King.

More sources about this topic:



http://www.qarlos.free.fr/navegacion/Sextante/formulas.htm

http://williams.best.vwh.net/sunrise_sunset_algorithm.htm

http://www.kevinboone.com/suntimes.html

http://star-www.st-and.ac.uk/~fv/webnotes/chapt12.htm