How to match common time?

Hi,

Person A and Person B wants to find a common time together for coffee. How do you make app like this?

I’m thinking on Airtable, Person A and Person B can store their availability as True/False at specific time. But to select that common time, it seems like a script is needed?

Perhaps there’s a proper way to design a scheduling app like this.

Why don’t Person A and Person B just call or SMS each other to fix a time?