The Google Calendar app allows you to view many calendars at once. You can create (and share) many different calendars or subscribe to calendars you got sent in an email or found on the internet. The calendars that make up your Google Calendar show on the left side of the screen and can be toggled on and off by selecting the checkbox.
Step 1
Open Google Calendar
A. Open Google Chrome.
B. Select the Google Calendar icon from the waffle menu
OR go to calendar.google.com.
Step 2
Select +
A. Select the '+' icon at the left next to 'Other calendars'
B. In the menu that appears, select 'From URL'
Step 3
Copy the calendar URL
Some Google Calendars found online have a link in the bottom left corner labeled 'Add to Google Calendar'. Selecting it will do the proceeding two steps for you and add the correct URL into the box in the next step. If you have access to the full URL you can also navigate to it in a different tab and copy it so it is ready to be pasted into your calendar.
Step 4
Paste and Add the calendar URL
A. Paste the calendar URL in the box labeled 'URL of calendar'
B. Select the 'Add calendar' button
The calendar should now be listed on the left side of your Google Calendar. You can check the box next to its name to remove and replace it in your full Google Calendar view.