How to display time based on the particular timezone? | Learning Curve- Perfect Tutorial for the beginers

<?php
function converttimezone($fromtime, $fromtimezone, $totimezone) {

   $from = new DateTimeZone($fromtimezone);
   $to = new DateTimeZone($totimezone);

   $originaltime = new DateTime($fromtime, $from);
   $totime = new DateTime($originaltime->format("c"));
   $totime->setTimezone($to);
   return $totime;
}


$display_converted_time = converttimezone("2014-05-27 15:01:00", "Asia/Calcutta", "America/Louisville");
echo $display_converted_time->format("Y-m-d H:i:s");
echo "\n";

?>

<?php

function converttimezone($fromtime, $fromtimezone, $totimezone) {

$from = new DateTimeZone($fromtimezone);

$to = new DateTimeZone($totimezone);

$originaltime = new DateTime($fromtime, $from);

$totime = new DateTime($originaltime->format("c"));

$totime->setTimezone($to);

return $totime;

}

$display_converted_time = converttimezone("2014-05-27 15:01:00", "Asia/Calcutta", "America/Louisville");

echo $display_converted_time->format("Y-m-d H:i:s");

echo "\n";