On a-cat.org we have an international A-Cat event calendar, and it holds a couple of nice features.
First of all you can view all events in one place, making it a bit easier to plan your season. Just over the calendar you can pick which countries you want to show in the calendar (as default all are shown). Be aware that you can pick multiple countries, if you fore instance just want to show your own country and the once near by.
Another feature that might be useful, is that you can get a calendar feed to import into your personal calendar, if it supports the iCal format. We have tested this in Googles calendar, and it seems to work just fine. At the top of the calendar you'll find a link to a more detailed description on what the links to the feeds are. Again you can choose all, or just country specific calendars.
But for this to be useful, we need all countries to report their events! So far only Poland, France and Denmark have reported their events, if you are aware of events (or maybe know the calendar responsible of your country), please send information to webmaster(at)a-cat.org.