PHP | date_sunset() Function

The date_sunset() is an inbuilt function in PHP which is used to find the sunset time for a specified day and location.

Syntax:

date_sunset ( $timestamp, $format, $latitude, $longitude, $zenith, $gmtoffset )

Parameters: This function accepts four parameters as mentioned above and described below.

• $timestamp: It is a required parameter which specifies the timestamp of the day from which the sunset time is taken.
• $format: It is an optional parameter which specifies the format to return the result. Return format are given below:
  • SUNFUNCS_RET_STRING: Returns a string. e.g. 16:46 (by default)
  • SUNFUNCS_RET_DOUBLE: Returns a float. e.g. 16.12345
  • SUNFUNCS_RET_TIMESTAMP: Returns the result as integer (timestamp). e.g. 987123569
• $latitude: It is an optional parameter which specifies the latitude of the location. By default, it set as North. To specify a value for South, pass in a negative value.
• $longitude: It is an optional parameter which specifies the longitude of the location. By default, it set as East. To modify a value for West, pass in a negative value.
• $zenith: It is an Optional parameter. The zenith is the angle between the center of the sun and a line perpendicular to earth’s surface, by default it is date.sunset_zenith.
• $gmtoffset: It is optional parameter and used to specifies the difference between GMT and local time in hours.

Return Value: It returns the time of the sunset, in the specified format, on success. FALSE on failure.

Exceptions: This function generates E_NOTICE error if date/time function is invalid and E_STRICT or E_WARNING if using the system setting or the TZ environment variable.

Below programs illustrate the date_sunset() function in PHP.

Program 1:

<?php
// PHP program to show sunset time
// of New delhi india for current day

// Longitude and latitude of Delhi India
// 28.6139° N, 77.2090° E
// GMT(Greenwich Mean Time) +5.30
// Zenith ~= 90

echo date("D M d Y");
echo("\nSunset time: ");
echo(date_sunset(time(), SUNFUNCS_RET_STRING,
                 28.6139, 77.2090, 90, 5.30));
?>

Output:

Wed Jun 27 2018
Sunset time: 19:07

Program 2:

<?php
// PHP program to show sunset time
// of GFG Noida for a Current day

// Longitude and latitude of GeeksforGeeks
// Noida 28°30'04.0"N 77°24'36.0"E
// GMT(Greenwich Mean Time) +5.30
// Zenith ~= 90

echo date("D M d Y");
echo("\nSunset time: ");
echo(date_sunset(time(), SUNFUNCS_RET_STRING,
              28.501120, 77.409989, 90, 5.30));
?>

Output:

Wed Jun 27 2018
Sunset time: 19:06

Reference: http://php.net/manual/en/function.date-sunset.php