PHP MongoDate: invalid output using MongoDate-> toDateTime ()

Question

PHP MongoDate: invalid output using MongoDate-> toDateTime ()

I have a strange error with MongoDate.

First: the system is a virtual machine on a Mac server.

Linux vm 3.16.0-33-generi # 44 ~ 04.14.1-Ubuntu SMP Fri Mar 13 10:32:52 UTC 2015 i686 i686 i686 GNU / Linux

<?php

    $n = 1420124400;
    echo $n."\n";

    $d = new MongoDate($n);
    var_dump( $d );
    var_dump( $d->toDateTime() );
    var_dump( new DateTime("@".$d->sec) );
?>

I got this result:

object(MongoDate)#1 (2) {
  ["sec"]=>
  int(1420124400)
  ["usec"]=>
  int(0)
}
object(DateTime)#2 (3) {
  ["date"]=>
  string(19) "1969-12-14 12:37:05"
  ["timezone_type"]=>
  int(1)
  ["timezone"]=>
  string(6) "+00:00"
}
object(DateTime)#2 (3) {
  ["date"]=>
  string(19) "2015-01-01 15:00:00"
  ["timezone_type"]=>
  int(1)
  ["timezone"]=>
  string(6) "+00:00"
}