iCal .ics files are commonly used to import meetings and events from one calendar system into another. Once downloaded, these files can be imported into Outlook calendars, but the method may not be obvious for Mac users.
METHOD 1 - Drag and Drop
Download .ics file
Drag and drop .ics file to either of the following targets...
Outlook icon in the "dock" at the bottom of the screen
Outlook calendar grid (any day of week or month)
Regardless of what day was selected for the drop, the import process will be initiated for whatever dates/times are contained in the .ics file.
METHOD 2 - Change which application "Opens" .ics files
Download .ics file
Right-click on file and select "Get Info" (or click once on file and select "File" > "Get Info" from top menu bar)
Change "Open with:" to Microsoft Outlook
Click "Change All..." button so that all future .ics files will also open in Outlook
When you double-click any .ics file, Outlook will attempt to open it and start the import process.