Notion Calendar - All of your commitments, now in one place. Meet the beautifully designed, fully integrated calendar for your work and life.
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.
Clockwise.com - A suite of tools that give individuals and teams the time and focus to accomplish their priorities
Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
Google Calendar - Spend less time managing your day & more time enjoying it
Alkanzo - Take control of your time. Alkanzo's AI smartly manages your schedule to help you in protecting schedule from back-to-back meetings, protecting time to deeply focus on work and completing high-priority tasks on time.