You can view someone else's calendar if they've shared it with you. You can also request access if they haven't shared their calendar with you yet.
Show or hide a calendar you're subscribed to
To add a calendar, go to calendar.google.com. You can show or hide calendars you’ve subscribed to.
- Open the Google Calendar app
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- Tap Menu
Settings
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- Tap the calendar you want to view.
- To find more available calendars, tap Show more.
- Turn Sync on or off.
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Settings 
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