After downloading the .ics file, follow these steps to import it into your calendar application:

Google Calendar

1. Open Google Calendar
2. Click the Settings gear icon (top right)
3. Select Settings from the menu
4. In the left sidebar, click Import & Export
5. Click Select file from your computer
6. Choose the downloaded .ics file
7. Select which calendar to add the events to
8. Click Import

Apple Calendar (iCal)

1. Option 1: Double-click the downloaded .ics file
2. Option 2: Open Calendar app, go to File → Import, and select the .ics file
3. Choose which calendar to add the events to
4. Click OK

Outlook

1. Open Outlook
2. Go to File → Open & Export → Import/Export
3. Select Import an iCalendar (.ics) or vCalendar file
4. Click Next, browse to the .ics file, and click OK