Apple’s Ical cannot read and write from the same online calendar. This is a workaround, assuming that there is only one person who updates the calendar.

The problem

Ical cannot both subscribe to a calendar and publish to the same calendar using Webdav.

The idea

Publish the local version of the calendar.

Requirements

• The calendar has only one author
• You should know your way around the terminal
• The calendar file(s) are in ~/Library/Calendars.

The solution

This is what I did, and I don’t know shit about OSX (yeah, the thing where they take other people’s work and slap their logo on it and then don’t give back).

1. Fetch a copy of the calendar from the net. This will create a whole bunch of .ics files. Why Apple doesn’t have one big file for the calendar events I don’t know.
2. Create a new local calendar
3. Close Ical
4. Copy the Events directory from the copy to the new local calendar
5. Delete the Calendar Cache file. I think it was called something like that. It’s in the Calendars directory, at any rate. This will force Ical to reload all the calendars.
6. Start Ical
7. Publish the newly-created local calendar to the Webdav address

Now, when the author creates a new event both the author and the people subscribing to the online copy of the calendar will see the changes.

The other solution is to use the free and open calendar program Mozilla Sunbird, but it’s not as shiny as Ical so Mac people won’t like it.