date_sub
I have been working on my own php script to get current down or up for sun and moon. I had to add function for any places that have 24 hour sun.
here is my code for places with 24 hour sun.
<?php
if ($sunrise == 0 && $sunset == 0) {
$sunrise24 = "";
$sunset24 = "";
//run suninfo
$sunup = date_sun_info(strtotime($year."-".$month."-".$day), $lat, $lon);
}
//check if sun is up all day.
if ($sunup[sunrise] == 1 && $sunup[sunrise] == 1) {
imagecopy($sky, $sun, 60, 20, 0, 0, $sun_width, $sun_height);
imagefill($sky, 0, 0, $bluesky);
}
?>
date_sun_info
(PHP 5 >= 5.1.2)
date_sun_info — Returns an array with information about sunset/sunrise and twilight begin/end
Description
array date_sun_info
( int
$time
, float $latitude
, float $longitude
)Parameters
-
time -
Timestamp.
-
latitude -
Latitude in degrees.
-
longitude -
Longitude in degrees.
Return Values
Returns array on success or FALSE on failure.
Examples
Example #1 A date_sun_info() example
<?php
$sun_info = date_sun_info(strtotime("2006-12-12"), 31.7667, 35.2333);
foreach ($sun_info as $key => $val) {
echo "$key: " . date("H:i:s", $val) . "\n";
}
?>
The above example will output:
sunrise: 05:52:11 sunset: 15:41:21 transit: 10:46:46 civil_twilight_begin: 05:24:08 civil_twilight_end: 16:09:24 nautical_twilight_begin: 04:52:25 nautical_twilight_end: 16:41:06 astronomical_twilight_begin: 04:21:32 astronomical_twilight_end: 17:12:00
See Also
- date_sunrise() - Returns time of sunrise for a given day and location
- date_sunset() - Returns time of sunset for a given day and location
add a note
User Contributed Notes
date_sun_info
ELY M.
08-Oct-2010 09:42
mother at localsnow dot com
23-Jun-2010 02:55
We needed the length of the day, both sunrise to sunset and twilight to twilight for particular latitudes. Sun_info() is just the thing. We mistakenly thought 'transit' was this value, which it is not. Transit is the time of day the sun is at its zenith. To get length of day, one must perform math on the results of sun_info().
When doing math with time values, don't expect date() to do the conversion to hours:minutes:seconds. date() thinks the passed value is a time since the epoch. You will need to do your own conversion to hours:minutes:seconds, using something like the following:
<?php
function hms($val) {
// convert seconds to hours:minutes:seconds
$v=$val;
$h=intval($v/3600);
$v-=($h*3600); // subtract hours
$m=intval($v/60);
$v-=($m*60); // subtract minutes
$s=$v % 60; // seconds remaining
if ($h<10) {$h="0".$h;}
if ($m<10) {$m="0".$m;}
if ($s<10) {$s="0".$s;}
return $h.":".$m.":".$s;
}
?>
Regarding date_sunrise() and date_sunset(), these both return values without seconds and without correction for Daylight time. Whereas sun_info() handles seconds as well as Daylight time. It even handles dates prior to the epoch correctly as negative timestamps, at least as of php 5.2.12
For example,
sun_info(strtotime('July 4, 1776'),47.3506,-122.6417)
produces something like the following when using date_default_timezone_set('America/Los_Angeles') and
date("H:i:s", $val)
sunrise: 04:20:26 [-6106016374]
sunset: 20:09:03 [-6105959457]
transit: 12:14:45 [-6105987915]
civil_twilight_begin: 03:40:54 [-6106018746]
civil_twilight_end: 20:48:35 [-6105957085]
nautical_twilight_begin: 02:46:58 [-6106021982]
nautical_twilight_end: 21:42:31 [-6105953849]
astronomical_twilight_begin: 01:28:06 [-6106026714]
astronomical_twilight_end: 23:01:23 [-6105949117]
* * *
glenbo (_AT_) mac (_DOT_) com
17-Jun-2008 12:54
It should be noted that for extreme geographical locations date_sun_info() might return unexpected values. Values of 1 or empty may be returned. If you are expecting a unix timestamp this will default to the epoch, or epoch+1, which is not what you would expect.
After researching official almanac records for these locations it appears likely that for sunrise and sunset return values of 1 relate to a situation where the sun is above the horizon for the entire 24 hour day. It is also possible that empty return values relate to a situation where the sun is below the horizon for the entire 24 hour day. In the case of twilight data a 1 probably means that the sun never dips below that zenith, and an empty value means the sun never rises above said zenith for that given day.
The following code exhibits unique dates from the northernmost city Ny-Ålesund, Svalbard, and the southernmost city McMurdo Research Station, Antarctica.
<?php
$northernmost_city_latitude = 78.92; // Ny-Ålesund, Svalbard
$northernmost_city_longitude = 11.93;
$southernmost_city_latitude = -77.88; // McMurdo Research Station, Antarctica
$southernmost_city_longitude = 166.73;
print_r( date_sun_info( strtotime("2008-01-01") , $northernmost_city_latitude, $northernmost_city_longitude) );
print_r( date_sun_info( strtotime("2008-04-01") , $northernmost_city_latitude, $northernmost_city_longitude) );
print_r( date_sun_info( strtotime("2008-01-01") , $southernmost_city_latitude, $southernmost_city_longitude) );
print_r( date_sun_info( strtotime("2008-06-01") , $southernmost_city_latitude, $southernmost_city_longitude) );
?>
This will return the following. Observe that sometimes a value of 1 or empty is returned.
Array
(
[sunrise] =>
[sunset] =>
[transit] => 1199186158
[civil_twilight_begin] =>
[civil_twilight_end] =>
[nautical_twilight_begin] => 1199184075
[nautical_twilight_end] => 1199188241
[astronomical_twilight_begin] => 1199170475
[astronomical_twilight_end] => 1199201840
)
Array
(
[sunrise] => 1207019232
[sunset] => 1207077865
[transit] => 1207048548
[civil_twilight_begin] => 1
[civil_twilight_end] => 1
[nautical_twilight_begin] => 1
[nautical_twilight_end] => 1
[astronomical_twilight_begin] => 1
[astronomical_twilight_end] => 1
)
Array
(
[sunrise] => 1
[sunset] => 1
[transit] => 1199148994
[civil_twilight_begin] => 1
[civil_twilight_end] => 1
[nautical_twilight_begin] => 1
[nautical_twilight_end] => 1
[astronomical_twilight_begin] => 1
[astronomical_twilight_end] => 1
)
Array
(
[sunrise] =>
[sunset] =>
[transit] => 1212281461
[civil_twilight_begin] =>
[civil_twilight_end] =>
[nautical_twilight_begin] => 1212273312
[nautical_twilight_end] => 1212289609
[astronomical_twilight_begin] => 1212264187
[astronomical_twilight_end] => 1212298734
)