While it’s useful being able to keep track of your events, the real power of Calendar comes when you grant access to others. However, in order to share your calendar you need to log into your Google account via a desktop browser.
Once you have Google Calendar in your web browser, on the far left of the screen, click on the drop-down tab next to the relevant calendar under ‘My calendars’. From here, choose ‘Share this Calendar’. Now you can specify the email address of the person who will have access to the calendar (it needs to be a Google account user) and what permission they are granted; for example, ‘See all event details’.
Once the Save button has been selected, the calendar is now sharable. However, if you now add an event to it on your phone’s Calendar app, you can scroll to the bottom to set the privacy option (from default to private); this way, even if a share is in place, it will prevent them from seeing the entry fully.