Event Calendar App - A simple, easy to manage, way of displaying events
Superpowered - Power through the day without your calendar
Plan - Plan is a better way to organize.
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.
Whenever - Casual calendar app for iOS
InstaCal - The missing menu bar calendar for MacOS