Sunbird: calendar files (.ics): where do they go?

I realize that this may not be a portable Sunbird issue, but I couldn't find any discussions on it in the mozilla forums, so I am seeking help here.

I downloaded a number of calendar files in the .ics extension. I tried putting them in the PortableSunbird\profile\Calendar directory, but nothing happens, and I don't see any calendars showing up. Is this the right place for the .ics files?

Thanks in advance.