request at =>2018-12-17 10:06:54
response at =>2018-12-17 10:06:57

source =>

<?php
echo "request at =>" . date('Y-m-d H:i:s') . "\n";
sleep(3);
echo "<br/>\n";
echo "response at =>" . date('Y-m-d H:i:s') . "\n";