You can maintain a calendar in Zimbra Desktop for each of your accounts.
Zimbra account calendars are synchronized with Zimbra Desktop Client. When you add a new event, change an event or delete an event from the Zimbra Desktop, the changes are synchronized back to your calendar in your Zimbra account.
You can maintain a calendar in Zimbra Desktop for each of your other accounts, but the calendar events are not synchronized back to your account calendars for those accounts.
If you are using another calendar program, you can save it as an iCalendar (.ics) file and import it into your calendar. If you make any changes to the calendar in Zimbra Desktop, the changes do not sync back to the calendar. If you reload the .ical calendar, the calendar on your Zimbra Desktop is over-written and any events you added are lost.
To learn more about reading, replying and forwarding messages with the ITG Zimbra Desktop client, please browse through the Managing your Calendars guide.
If you are not able to find the information you are looking for, please contact the ITG Help Desk at extension 8044 or email@example.com.