date_sunset
Returns time of sunset for a given day and location
Warning
This function has been DEPRECATED as of PHP 8.1.0.
Relying on this function is highly discouraged. Use
date_sun_info instead.
Description
stringintfloatfalse date_sunset(
int $timestamp
,
int $returnFormat
= SUNFUNCS_RET_STRING
,
floatnull $latitude
= null
,
floatnull $longitude
= null
,
floatnull $zenith
= null
,
floatnull $utcOffset
= null
)
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_zenith
Common zenith
angles
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 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.
Errors/Exceptions
Every call to a date/time function will generate a E_WARNING
if the time zone is not valid. See also date_default_timezone_set
Examples
Example #1 date_sunset example
<?php
/* calculate the sunset time for Lisbon, Portugal
Latitude: 38.4 North
Longitude: 9 West
Zenith ~= 90
offset: +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: