Something that seems to have not been mentioned in the new forums, but was immensely useful to me to automatically import calendar data in my OC9.1 server. I hope that the original author, @tschunschi, will excuse me for hijacking his post and transferring it here 
https://forum.owncloud.org/viewtopic.php?f=8&t=34306
Hey,
just wanted to share this:
I need to import ICS files from the web periodically (like Facebook calendar feeds, Google calendars, calendars from other ownCloud instance etc…). This is something oC calendar unfortunately doesn't support out of the box. I used to use something like www.birchpress.com/forums/topic/import-calendar-to-owncloud to accomplish this (using OC_Calendar_Import). After the calendar app rewrite this function is gone.
Feel free to try out my pure CalDAV-based solution:
www.github.com/buzz/ics2owncloud.py
Feedback & pull-requests welcome!