Import a vCalendar file into Calendar
On the File menu, click Import and Export.
Click Import an iCalendar or vCalendar file (.vcs).
In the Look in box, click the drive that contains the vCalendar appointment you want. In the folder list, double-click folders until you can click the vCalendar file you want to import.
Click OK.
Tip You can also double-click the vCalendar file or drag it onto Calendar on the Outlook bar. These methods work best with a single vCalendar appointment because only the first appointment in a file is imported when you double-click or drag the file.