date_sunset

Returns time of sunset for a given day and location

This function has been DEPRECATED as of PHP 8.1.0. Relying on this function is highly discouraged. Use `date_sun_info` instead.

&reftitle.description; #[\Deprecated] ``string``int``float``false```date_sunset` `int` `timestamp` `int` `returnFormat` `SUNFUNCS_RET_STRING` ``float``null```latitude`&null; ``float``null```longitude`&null; ``float``null```zenith`&null; ``float``null```utcOffset`&null;

`date_sunset` returns the sunset time for a given day (specified as a `timestamp`) and location.

&reftitle.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`.

&reftitle.returnvalues;

Returns the sunset time in a specified `returnFormat` on success&return.falseforfailure;. 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.

&reftitle.errors; &date.timezone.errors.description;
&reftitle.changelog;

&Version; | &Description;
8.1.0 | This function has been deprecated in favor of `date_sun_info`.
8.0.0 | `latitude`, `longitude`, `zenith` and `utcOffset` are nullable now.

&reftitle.examples;

### `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);

    ?>

&example.outputs.similar;

    Mon Dec 20 2004, sunset time : 18:13

### No sunset

    <?php
    $solstice = strtotime('2017-12-21');
    var_dump(date_sunset($solstice, SUNFUNCS_RET_STRING, 69.245833, -53.537222));
    ?>

&example.outputs;

    bool(false)

&reftitle.seealso;

- `date_sun_info`