Creating a Google Calendar app Edit

In Chrome, go to https://calendar.google.com/
From the Chrome (three-dots) menu, go to "Cast, Save, and Share"
Choose "Install Page as App…"
Pick a name; the app will be saved to ~/Applications/Chrome Apps/

Use case:

In iStat Menus, you can customize the items at the bottom of each menu. In the date/time menu, set one of the icons to open the calendar app.

See also

Stack Exchange answer about creating a shortcut that uses a secondary account.

wiki