Somebody please help me!

I am trying to migrate our institute's group calendar to Zimbra calendar and hit some walls here. Our old calendar system uses another program which uses Postgres database to hold all calendar info and there is no way to export the data to zimbra directly. I tried to reformat the data to ical format and used curl command to post data directly to zimbra. For single appointments they are correctly appeared in zimbra calendar. But for meetings I seemed not linking all attendees to the organizer unless I login to zimbra as the organizer, open the meeting and re-save the meeting then all the attendees will get the invitation email After attendee accepted the meeting then it will appear in the attendee's calendar. We have more than 200 people in our institute and this is definitely not the right way to migrate a calendar. My supervisor thinks using soap may help. I have been looking at the examples using perl/soap module on the /ZimbraServer/src/perl/soap/ and have some difficulty to run the sample script createAppt.pl. I have installed all required modules on the server and run "perl createAppt.pl $meetingTitle $startdate $enddate" which will create a 3 people meeting. But no matter what format of startdate and enddate I tried I always get the error

RESPONSE:
--------------
<ns0:Fault xmlns:ns0="http://www.w3.org/2003/05/soap-envelope">
<ns0:Code>
<ns0:Value>soap:Sender</ns0:Value>
</ns0:Code>
<ns0:Reason>
<ns0:Text>invalid request: Caught ParseException: java.text.ParseException: Invalid date/time specified: 2007-09-27T12:00:00</ns0:Text>
...

I have tried "20070927 12:00:00-04", "20070927T120000z", "20070927T120000" and "2007-09-27T12:00:00". Nothing worked.

Have any of you tried this successfully and what is the date format you used? If you have successfully migrated the calendar, could you please share your method(s)? Thanks in advance,

Jing