<?php
date_default_timezone_set('America/Mexico_City');
$time=time();

echo $time."\n";

echo date("H:i:s",$time);

$time=strtotime('6:30 pm');
echo "\n\n".$time."\n";

echo date("H:i:s",$time);
?>

1566410589
13:03:09

1566430200
18:30:00