UTC_TIMESTAMP() to user defined timezone?

UTC_TIMESTAMP() to user defined timezone?

I am storing timestamps in my db using UTC_TIMESTAMP().
I want to output them based on user selected timezone. I tried writing a
small function to do this, however, it does not output correctly.
// Date/time converter
function convertTZ($date, $tz, $tzFormat)
{
$date = new DateTime($date);
$date->setTimezone(new DateTimeZone($tz));
return $date->format($tzFormat);
}
echo $_SESSION['dtCurrLogin'].'<br />';
echo convertTZ($_SESSION['dtCurrLogin'], 'UTC', 'F j, Y @ g:i:s a e');
dtCurrLogin from db = 2013-09-12 01:23:45
the above outputs :
2013-09-12 01:23:45 September 12, 2013 @ 5:23:45 am UTC
Obviously this is not correct as I went from UTC to UTC so they should be
equal. If I change to output EST then it shows 1:23:45 am, but of course
that would not be right either.