request at =>2018-11-15 08:24:33
response at =>2018-11-15 08:24:36

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";