$tz = new DateTimeZone('Asia/Kolkata'); //Change your timezone
$date = date("Y-m-d h:i:sa"); //Current Date
$a = new MongoDB\BSON\UTCDateTime(strtotime($date)*1000);
$datetime = $a->toDateTime();
echo '<pre>';print_r($datetime);echo '</pre>';
$datetime->setTimezone($tz); //Set timezone
$time=$datetime->format(DATE_ATOM); //(example: 2005-08-15T15:52:01+00:00)
echo "<br>". $time . "<br>";
OUTPUT :
//Output of datetime object
DateTime Object
(
[date] => 2016-08-09 14:57:06.000000
[timezone_type] => 1
[timezone] => +00:00
)
//Output of time
2016-08-09T20:27:06+05:30