There is an open standard for calendars, the so-called iCalendar specification, which allows programs like the Calendar app to subscribe to and automatically update MacOS Online calendars. Most calendar apps support this format, including Google Calendar.
Add a new Calendar Subscription
Open the Calendar app from the Dock or the Applications folder. From the main window, you can add a new calendar subscription by choosing File> New Calendar Subscription in the top menu bar or by pressing Option + Command + S.
This will open a window In the window you will be asked for a URL containing a link to a file with the extension
.ics . Depending on which calendar you want to subscribe to, the way this link is accessed may vary. In this example, we use Google Calendar.
For Google Calendar, you can find the link by going to Settings, clicking the calendar in the sidebar, and scrolling down to the bottom of a box labeled "iCal Secret Address."
Copy this address and paste it into the Calendar app dialog. If the URL is not an iCalendar link, an error message will be displayed. If this worked, the following screen appears with the subscription settings.
Key Points to Remember The name you want to call in the Calendar app, and how fast it syncs with your Google Calendar. The default value is once a week. You can refresh it every five minutes (or not). You can also change the color of events using the drop-down list next to the name.
Press "OK" when you have changed the settings. If everything works, a new box will appear in the sidebar and new events will appear in your calendar.
You can hide and show this option to show and hide the subscription. Subscribe to the subscription completely by right-clicking on it in the sidebar and choosing "Unsubscribe." " choose. You can edit the settings via the same context menu by selecting "Get information" where you can change the update time.