I had instaler the zimbra desktop in my laptop , but I have a problem with the date and my calender don't work

In my laptop the date is

jrios@jjjoshh-lap:~$ date
mar jun 1 07:22:54 VET 2010

The feature set in the zimbra desktop is GTM-430 Caracas

But when send the e-mail for zimbra desktop , the header e-mail is

Enviados: Martes, 1 de Junio 2010 19:23:03 (GMT+1930) Auto-Detected

The problem is the GTM+1930 , but i dont no , where the change this features.

S.O. = Ubuntu 9.10
The date in the zimbra server is OK

Please help me !!!!