Wrong date from timestamp

<?php
    $z=$GLOBALS['argv'][1];
    $date=date('Y-m-d H:m:s',$z);
    echo $z."\n";
    echo $date."\n";
    echo strtotime($date)."\n";
?>

When I pass 1307433995 its ok

1307433995
2011-06-07 10:06:35
1307433995

but when I pa开发者_如何学运维ss 1307436121 it`s something weird...

1307436121
2011-06-07 10:06:01
1307433961

Any help?

---

Minutes is i not m in the time formatting.