Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.
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
BusyCal - powerful calendar app for macOS
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.
Lightning Calendar - Organize your life — it’s about time!