We can use the below script to subtract half an hour from the given time in PHP.
<?php
date_default_timezone_set(‘UTC’);
$actualTime = strtotime(‘2010-07-28 15:00:00′);
$modifiedTime = $actualTime – strtotime(’00:30:00’);
echo “Modified time: ” . date(“H:i a”, $modifiedTime);
?>
Above script gives the output as
Modified time: 14:30 pm