date_sunset | Functions | PHP

Returns time of sunset for a given day and location

Syntax

date_sunset ( int $timestamp [, int $returnFormat = SUNFUNCS_RET_STRING [, float $latitude = ini_get("date.default_latitude") [, float $longitude = ini_get("date.default_longitude") [, float $zenith = ini_get("date.sunset_zenith") [, float $utcOffset = 0 ]]]]] ) : mixed

Parameters

timestamp

The timestamp of the day from which the sunset time is taken.

returnFormat

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

latitude

Defaults to North, pass in a negative value for South. See also: date.default_latitude

longitude

Defaults to East, pass in a negative value for West. See also: date.default_longitude

zenith

zenith is the angle between the center of the sun and a line perpendicular to earth's surface. It defaults to date.sunset_zenith

Angle	Description
90°50'	Sunset: the point where the sun becomes invisible.
96°	Civil twilight: conventionally used to signify the end of dusk.
102°	Nautical twilight: the point at which the horizon ends being visible at sea.
108°	Astronomical twilight: the point at which the sun ends being the source of any illumination.

utcOffset

Specified in hours. The utcOffset is ignored, if returnFormat is SUNFUNCS_RET_TIMESTAMP.

Return

Returns the sunset time in a specified returnFormat on success or FALSE on failure. One potential reason for failure is that the sun does not set at all, which happens inside the polar circles for part of the year.

Examples

timestamp

<?

$timestamp = time();

$return = date_sunset($timestamp);

echo $return;

?>

14:36

returnFormat | SUNFUNCS_RET_STRING

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_STRING;

$return = date_sunset($timestamp, $returnFormat);

echo $return;

?>

14:36

returnFormat | SUNFUNCS_RET_DOUBLE

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_DOUBLE;

$return = date_sunset($timestamp, $returnFormat);

echo $return;

?>

14.612694753592

returnFormat | SUNFUNCS_RET_TIMESTAMP

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_TIMESTAMP;

$return = date_sunset($timestamp, $returnFormat);

echo $return;

?>

1639060605

latitude

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_STRING;
$latitude = 44.36;

$return = date_sunset($timestamp, $returnFormat, $latitude);

echo $return;

?>

14:01

longitude

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_STRING;
$latitude = 44.36;
$longitude = -110.30;

$return = date_sunset($timestamp, $returnFormat, $latitude, $longitude);

echo $return;

?>

23:43

zenith

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_STRING;
$latitude = 44.36;
$longitude = -110.30;
$zenith = 90.58;

$return = date_sunset($timestamp, $returnFormat, $latitude, $longitude, $zenith);

echo $return;

?>

23:41

utcOffset

<?

$timestamp = time();
$returnFormat = SUNFUNCS_RET_STRING;
$latitude = 44.36;
$longitude = -110.30;
$zenith = 90.58;
$utcOffset = 1;

$return = date_sunset($timestamp, $returnFormat, $latitude, $longitude, $zenith, $utcOffset);

echo $return;

?>

00:41

No Sunset

<?

$timestamp = strtotime("2017-12-21");
$returnFormat = SUNFUNCS_RET_STRING;
$latitude = 69.245833;
$longitude = -53.537222;

$return = date_sunset($timestamp, $returnFormat, $latitude, $longitude);

var_export($return);

?>

false

Links

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