We use Zimbra Calendar to keep track of employees birthdays (or any other general events).
Our HR personnel is now add/remove dates on her own calendar then share with everyone.
If she'll leave the company someday, we can't edit, delete or view her calendar (/w unshared items like birthdays) properly (actually we can, first we reset her password, then log onto her account etc. etc.).
Now, we want to use a common calender (like Google Calendar birthdays' calendar) shared by everyone which can edit by zimbra administrators (or any user) so even if user left out our company, we can simply remove him/her from calendar admins and we can continue working.
Is this possible?