Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.

Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.

Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.

zcal - zcal is the fastest way to schedule every meeting for Free and make it personal.

Plan - Plan is a better way to organize.

TidyCal - Optimize your schedule with custom booking pages and calendar integrations