You can automate calendar backups by using the following Linux command and add it to a crontab on a server or machine to run on regular intervals:

curl -X GET -u <USER>:<PASS> <CALENDAR_URL> -o <OUTFILE.ICS>
<USER>
your email address, user@example.com
<PASS>
your email address password
<OUTFILE.ICS>
The location where you want to save the resulting .ics file.
<CALENDAR_URL>
Can be found when you log into Zimbra. Select the calendar you want to download, and select Share Calendar. The URL will be given as a link at the bottom of the new window that opens. You want the one that mentions “ICS”.


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