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Import ICS feed to Outlook
Open Calendar Outlook and click File -> Open & Export -> Import/Export.
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Add calendar
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Select Upload from file → Click Browse → Import an iCal (.ics) or vCalendar (.vcs) and click Next.
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Browse to the location of the ICS file that you want to import into Outlook, select it, and click OK.
A dialog box will appear. Click the Import button to to actually import the data to your calendar (or click the Open as new button if you want Outlook to create a new calendar folder to store your imported calendar appointments).
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Import ICS feed to Apple Calendar
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