I have a Google calendar that I want to view in Zimbra. I created a new calendar folder in Zimbra and put in the Google calender URL (the one ending in .ics).
Initially, the calendar shows up in Zimbra fine. However, if I add an event in the Google calendar the updates do not appear in Zimbra even if I do a refresh (hard or soft). Even waiting several hours does not work.
If I delete the shared folder in Zimbra and reshare, the new events do show up. It is as if you only get the events that were in existence in Google calendar when you initially shared it.