iCalendar message changing meeting time

Hello,

I am writing an app for work which uses JSP to create iCalendar objects and sends them to given recipients. This will allow us to sync our system proprietary calendar with Outlook. (Just for convenience reasons). I have been able to get it working to some degree so far. But, for some reason, when I change the DTSTART, DTEND, and DTSTAMP properties to be in UTC format (adding capital Z at the end for time zone reference) the meeting message comes up showing the wrong start and end time. ie. If I send a message about a meeting starting at 11:45am and ending at 12:15pm, the meeting confirmation message lists the time as starting at 7:45am and ending at 8:15am. Can someone please tell me why this is happening?

Here is the code for the iCalendar writer:

SimpleDateFormat iCalendarDateFormat = new SimpleDateFormat("yyyyMMdd'T'HHmm'00Z'");

java.util.Date startdate = DATE_PARSER.parse(request.getParameter("start_date"));
            java.util.Date enddate = DATE_PARSER.parse(request.getParameter("end_date"));
            String StartDate = DATEID.format(startdate) + "T" + request.getParameter("start_time") + "00Z";
            String EndDate = DATEID.format(enddate) + "T" + request.getParameter("end_time") + "00Z";

String calendarContent =
                "BEGIN:VCALENDAR\n" +
                "METHOD:REQUEST\n" +
                "PRODID: BCP - Meeting\n" +
                "VERSION:2.0\n" +
            "BEGIN: VTIMEZONE\n" +
            "TZID:US-Eastern\n" +
            "TZNAME:EST\n" +
            "BEGIN:STANDARD\n" +
            "DTSTART:16010101T020000\n" +
            "TZOFFSETFROM:-0400\n" +
            "TZOFFSETTO:-0500\n" +
            "RRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMONTH=11BYDAY=1SU\n" +
            "END:STANDARD\n" +
            "BEGIN:DAYLIGHT\n" +
            "DTSTART:16010101T020000\n" +
            "TZOFFSETFROM:-0500\n" +
            "TZOFFSETTO:-0400\n" +
            "RRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMONTH=3;BYDAY=2SU\n" +
            "END:DAYLIGHT\n" +
            "END:TIMEZONE\n" +
                "BEGIN:VEVENT\n" +
                "DTSTAMP:" + iCalendarDateFormat.format(stamp) + "\n" +
                "DTSTART:" + StartDate + "\n" +
                "DTEND:"  + EndDate + "\n" +
                "SUMMARY:" + request.getParameter("subject") + "\n" +
                "UID:324\n" +
                "ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE:MAILTO:" + request.getParameter("to") + "\n" +
                "ORGANIZER:" + request.getParameter("from") + "\n" +
                "LOCATION:" + request.getParameter("location") + "\n" +
                "DESCRIPTION:" + request.getParameter("comments") + "\n" +
                "SEQUENCE:0\n" +
                "PRIORITY:5\n" +
                "CLASS:PUBLIC\n" +
                "STATUS:CONFIRMED\n" +
                "TRANSP:OPAQUE\n" +
                "BEGIN:VALARM\n" +
                "ACTION:DISPLAY\n" +
                "DESCRIPTION:REMINDER\n" +
                "TRIGGER;RELATED=START:-PT00H15M00S\n" +
                "END:VALARM\n" +
                "END:VEVENT\n" +
                "END:VCALENDAR";

note:still WIP so some fields not completely realized yet.

Thanks in advance,

-Randal