Superpowered - Power through the day without your calendar
Google Calendar - Spend less time managing your day & more time enjoying it
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.
Mixmax Calendar - The fastest way to schedule meetings with anyone, anywhere
InstaCal - The missing menu bar calendar for MacOS
Sunsama - Calendar and scheduling for teams