I would like to share read-only calendars with, e.g.:
- Colleagues
- Close friends
- The world at large

However, I don’t want them all to have the same level of info.

Close friends might be able to see exactly what I’m doing. Colleagues can see the details of events in specific work calendars that I indicate, but only generic ‘busy’ blocks outside of working hours. The world at large can only see public events I am attending.

There’s some support for this available by having multiple calendars and sharing them with particular people of course, but it would only allow for different people seeing different versions of an event if I manually intervene to make my ‘Personal’ calendar items appear in my ‘Work’ calendar, but with edited information.

There is also the case where I have half a dozen different calendars for my own use, but would like to share one consolidated view of them. Outsiders don’t need to know how I’ve organised everything.

It occurs to me that the most generic way to solve this would be to support automatic duplication of events from one calendar into another. Without knowing the details of how your system works, it seems to me it wouldn’t be too hard to record a master-slave relationship between calendars and then simply duplicate across as a batch process or per-change.

The next step would be to indicate which event fields would survive the copy process, and which should be wiped (e.g. the name of the event if the slave calendar is intended to show only availability).

I would then have a series of ‘input’ calendars which I actually use, and ‘output’ calendars which I can share.

This could in fact be handled entirely outside the server if I could find a smart enough client which offers this inter-calendar syncing, but I have searched high and low and not found anything beyond digging in to the spec and writing some cron jobs which poll/post to the server directly.

Hope this seems like a good idea. With the right interface I think it could be a big selling point. People are more and more aware of privacy, and this would give great control without breaking any client software.

Idea for Paid Premium Pro Service:

Add a version history feature to Calendar and Adressbook data.

For me it is very important to preserve my Data. I live currently always in the danger to accidentally delete some of my data because of my own fault or by a software or synchronization error. If I sync my calendar across several devices using your or a similar service and delete 1 entry at the first device it gets automatically deleted at the second and vice versa.
The same goes to loosing partial data. If I edit a text field and the client software is outdated and supports only 50 characters at a headline and I had first a text of 80 placed into this field at my desktop I will lose the last 30 characters during a sync. Same goes to other similar actions. I'm unable to get this information later back because I can't compare what has changed and I know currently also no solution for this.

I would say your service could fill this gap! :-)

How to do this?

Create a web frontend to at least view the data stored at your cloud. It doesn't need to be a full functional calendar or adressbook. But it should display all fields which are contained at each dataset.

Now add a version history to this data on your server which is the big enhancement of CalDAV and CardDav and the power of this proposal. Make is possible to display changes between each sync if there were any modifications and make it possible to view deleted Items.

I hope you like my proposal and think seriously about it. I'm currently thinking about getting a Pro Account at your service only to support your Idea. Compared to the free I have currently no stimulus to upgrade. Such a "version history" feature would change this completely. And I think others would like to have more security, too.

Thanks a lot for creating a independent alterative to the big global players. Keep on the good work. :-)

One of the thing that prevent me and my family using the service is the fact that they need to create an account. Some people (who says the old ones ! :) ) tends to refuse creating account everywhere. It gives them the impression of security breach and it becomes difficult to remember every passwords.

So if they could sign in with their already existing facebook account or anything else it would be easier.

By the way I just saw that here on the forum we can log with facebook ang google whereas I did not see it on the main site.