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(1768981876) ["sunset"]=> int(1769013140) ["transit"]=> int(1768997508) ["civil_twilight_begin"]=> int(1768979737) ["civil_twilight_end"]=> int(1769015278) ["nautical_twilight_begin"]=> int(1768977262) ["nautical_twilight_end"]=> int(1769017753) ["astronomical_twilight_begin"]=> int(1768974885) ["astronomical_twilight_end"]=> int(1769020130) }