I am trying to combine CalDavZAP with the Roundup Issue Tracker http://www.roundup-tracker.org/. Roundup is a highly customizable, open source issue tracking system that can be used, for example, to track software bug fixing processes, customer support tickets, sales opportunities, etc. It supports datetime stamps in its database, but it does not come with an own calendar client in its web interface. However, it is easily expandable by Python scripts, which should allow to set up some interaction between Roundup and CalDavZAP in both directions.
For example, I want to generate calendar events from within Roundup’s web interface using a script that adds content to the .ics files. This should be no problem using the Python iCalendar package. In the other direction, from CalDavZAP to Roundup, I want Roundup to update its database if calendar events have been changed, added or removed. I think this can also easily be implemented by monitoring the directory where the .ics files live for changes using the PyWin32 package, and then parse the changed files for new content using iCalendar.