roundcube is interpreting the time (from headers) differently than other software

[avoidspam]

I couldn't figure out why email wasn't showing up in Roundcube, then I realized it was, but some emails are coming in different orders than Outlook or other web mails. I've included an unmodified header and explained the differences between roundcube and others below:

[Actual Email Header]:

From listmanager@domain.com Tue Aug 22 23:42:59 2006
Received: from domain.com (domain.com [1.2.3.4])
        by www.recipient.net (8.13.8/8.13.8) with ESMTP id k7N3gv6n007117
        for <user@recipient.net>; Tue, 22 Aug 2006 23:42:58 -0400 (EDT)
Received: (from root@localhost)
        by domain.com (8.11.6/8.11.6) id k7MKIE012883;
        Tue, 22 Aug 2006 14:18:14 -0600
Date: Tue, 22 Aug 2006 14:18:14 -0600
Message-Id: <200608222018.k7MKIE012883@domain.com>
To: user@recipient.net
Subject: Subject line
From: "Domain.com" <listmanager@domain.com>
Reply-To: listmanager@Domain.com
MIME-Version: 1.0
X-Mailer-ListID: 1
Content-Type: multipart/alternative;
     boundary="==MULTIPART_BOUNDARY_d371ede8e6ed06e699d32974b78ca58e"
X-Greylist: Sender DNS name whitelisted, not delayed by milter-greylist-2.0.2 
www.recipient.net [5.6.7.8]); Tue, 22 Aug 2006
 23:42:59 -0400 (EDT)
Content-Length: 11652
Status: RO
X-Status:
X-Keywords:
X-UID: 1196

In Outlook (and all other web based mail programs I currently use), it states the delivery time as Tue 8/22/2006 at 11:42 PM. In Roundcube, the mail is showing delivery time of Tuesday 8/22/2006 at 4:18 PM. I do not know if this is a bug or just the way roundcube is configured to run. In the above example, domain.com is the originating mail server and recipient.net is the recipient's domain.