Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

This is expected. Without converting to an integer with strtotime(), the DateTime object remembers which timezone it was created with. In this case the timezone it knows is "GMT-0500". If you use date(), this information is not available and it will use the default timezone. The following example shows this a bit better:

derick@kossu:/tmp$ cat bug46641.php 
<?php
date_default_timezone_set('Europe/Oslo');
$timestr = "2008-11-19 10:51:35.199665-05";

$outformat = "M j Y H:i:s T (e,I,O,P,T,Z)";

$obj = new DateTime($timestr);

print date($outformat, strtotime($timestr)) . "\n";
print $obj->format($outformat) . "\n";

?>

derick@kossu:/tmp$ php bug46641.php
Nov 19 2008 16:51:35 CET (Europe/Oslo,0,+0100,+01:00,CET,3600)
Nov 19 2008 10:51:35 GMT-0500 (-05:00,0,-0500,-05:00,GMT-0500,-18000)

Okay.  I can see this point, and thought something like that was 
involved, the transition through a timestamp.

However, I would still like to know how to get 'T' (and 'e') to return 
what I expect.  For example, I'd rather see 'EDT' than 'GMT-0500', and 
I still feel that '-05:00.0' instead of the expected long name may in 
fact be a [different] bug/error.

Do you know how I can resolve this?  It seems that setting the 
timezone of the DateTime causes the results of the 'T' and 'e' 
formatting parameter to work as expected.  If I set the timezone to date_default_timezone_get, or assumedly anything else, it will return 
the format I expect for 'e' and 'T'.

Is that the correct thing I should do to get the behaviour I expected?

Thanks.