Php/docs/function.date-sunset
date_sunset
(PHP 5, PHP 7)
date_sunset — Returns time of sunset for a given day and location
Description
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
date_sunset() returns the sunset time for a given
day (specified as a timestamp
) and location.
Parameters
timestamp
The
timestamp
of the day from which the sunset time is taken.returnFormat
- {|
|+
returnFormat
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 int (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_zenithCommon zenith
anglesAngle 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, ifreturnFormat
isSUNFUNCS_RET_TIMESTAMP
.
Errors/Exceptions
Every call to a date/time function will generate a E_NOTICE
if the time zone is not valid, and/or a E_STRICT
or E_WARNING
message
if using the system settings or the TZ
environment
variable. See also date_default_timezone_set()
Return Values
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
Example #1 date_sunset() example
<?php/* calculate the sunset time for Lisbon, PortugalLatitude: 38.4 NorthLongitude: 9 WestZenith ~= 90offset: +1 GMT*/echo date("D M d Y"). ', sunset time : ' .date_sunset(time(), SUNFUNCS_RET_STRING, 38.4, -9, 90, 1);?>
The above example will output something similar to:
Mon Dec 20 2004, sunset time : 18:13
Example #2 No sunset
<?php$solstice = strtotime('2017-12-21');var_dump(date_sunset($solstice, SUNFUNCS_RET_STRING, 69.245833, -53.537222));?>
The above example will output:
bool(false)
See Also
- date_sunrise() - Returns time of sunrise for a given day and location
- date_sun_info() - Returns an array with information about sunset/sunrise and twilight begin/end