Add your Google Calendar to macOS
If you don't have your Google Calendar connected to macOS, follow the steps below.
On your Mac, choose Apple menu → System Settings…
Choose Internet Accounts in the sidebar.
Choose the Add Account… button, and pick an account provider.
Enter your account name, password, and other requested information.
Once your account is added, ensure that Calendars are toggled On.
To update calendar events faster, open Calendar.app and adjust the Refresh Calendars option in Settings… → Accounts to Every minute.
(OPTIONAL) You can also set up Rewind to draft email summaries in Gmail by following these directions.
Note: It may take up to 30 seconds for recently added calendars to appear in the list of calendars in Rewind.