If other users have shared their calendars with you, you may view those calendars. If a user hasn't yet shared his or her calendar with you, you may send a request to that individual.
Requesting Access to Another User's Calendar:
Open Google Calendar.
Above the calendarlist on the left, begin typing a user's name or email address in the Add a coworker's calendar field:
Select the correct name from the list that appears.
You will now see the calendar under "Other calendars".
View a Calendar Shared by Another User:
There are multiple ways to view calendars shared with you by other users:
The Other calendars list on the left contains all calendars that have been shared with you. Clicking on the individual's name will display their calendar.
Even if you've already sent a request to have a calendar shared, you may still use the Add a coworker's calendar field to search for shared calendars. Clicking on the name of an already shared calendar will display the calendar itself rather than a request form.