Here is a link to the Google Document: How2Guide: Allow People to view your Google Calendar

First, go to your Google Calendar. 

Next click the ‘three vertical dots’ next to the Calendar you wish to share, the dots should look like the following image.       

Next please click and navigate to the ‘Settings and sharing’ page. 

Once you have navigated to the ‘Settings and sharing’ page please then go to the ‘Share with specific people’ section of the page.

In this section you can add specific people to view your calendar and give them permissions. 

Click the ‘Add people’ button. 

Next type in the person or group you wish to share your Calendar with. 

Once you have selected the person or group you wish to share your Calendar with then click the ‘Send’ button or press the ‘Enter’ key.

This should send an email to the group or person giving them access to your Calendar. 

To change permissions again please click or hover over the ‘three vertical dots’ next to the person or group. 

Then make the changes you wish by clicking one of the options.