Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Itsycal - Itsycal for Mac. Itsycal is a tiny menu bar calendar. If you want, it will display your events as a companion to the Mac Calendar app. You can also create and delete (but not edit) events. Download Itsycal for macOS 10.
Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
Lightning Calendar - Organize your life — it’s about time!
Rainlendar - Rainlendar - Customizable desktop calendar