The behaviour of these functions is affected by settings in php.ini.
| Name | Default | Changeable | Changelog | 
|---|---|---|---|
| date.default_latitude | "31.7667" | PHP_INI_ALL | Available since PHP 5.0.0. | 
| date.default_longitude | "35.2333" | PHP_INI_ALL | Available since PHP 5.0.0. | 
| date.sunrise_zenith | "90.583333" | PHP_INI_ALL | Available since PHP 5.0.0. | 
| date.sunset_zenith | "90.583333" | PHP_INI_ALL | Available since PHP 5.0.0. | 
| date.timezone | "" | PHP_INI_ALL | Available since PHP 5.1.0. | 
Here's a short explanation of the configuration directives.
The default latitude.
The default longitude.
The default sunrise zenith.
The default sunset zenith.
The default timezone used by all date/time functions if the TZ environment variable isn't set. The precedence order is described in the date_default_timezone_get() page. See List of Supported Timezones for a list of supported timezones.
Note: The first four configuration options are currently only used by date_sunrise() and date_sunset().