date_sub
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
)
date_sun_info
(PHP 5 >= 5.1.2)
date_sun_info — Returns an array with information about sunset/sunrise and twilight begin/end
Beschreibung
array date_sun_info
( int $time
, float $latitude
, float $longitude
)
Parameter-Liste
- time
-
Timestamp.
- latitude
-
Latitude in degrees.
- longitude
-
Longitude in degrees.
Rückgabewerte
Returns array on success or FALSE on failure.
Beispiele
Beispiel #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";
}
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
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
add a note
User Contributed Notesdate_sun_info
glenbo (_AT_) mac (_DOT_) com
17-Jun-2008 09:54
17-Jun-2008 09:54