PHP has a function for calculating sunset and sunrise—for Earth


<?php
$sun = date_sun_info(time(), 51.50, -0.127);
var_dump( $sun );
?>
Output
array(9) { ["sunrise"]=> int(1775452945) ["sunset"]=> int(1775501003) ["transit"]=> int(1775476974) ["civil_twilight_begin"]=> int(1775450986) ["civil_twilight_end"]=> int(1775502962) ["nautical_twilight_begin"]=> int(1775448476) ["nautical_twilight_end"]=> int(1775505473) ["astronomical_twilight_begin"]=> int(1775445746) ["astronomical_twilight_end"]=> int(1775508203) }