With Calendar Planner you can export your events in an iCal format file (.ics), to be used in any other Calendar application that supports this format.
iCal is the most used calendar file format around. You can import iCal files to Google Calendar, Apple's iCalendar, Yahoo! Calendar, Mozilla Thunderbird or Microsoft Outlook.
The iCal export function in Calendar Planner is very simple: you just need to filter the event results to include only those events you want to import, and on the results page, click on the "Export" button: