How to set available dates in a input type date

[kokolegorille]

The first thing You could do is ensure at the database level that there will be no overlapping appointments…

Elixir Blog Posts

Today’s blog post is about exclusion constraints in Postgres and how to prevent double-bookings of appointments with them. It’s a nice dive into how to execute custom SQL code in your migrations and how timestamp ranges work in Posgres. You can use this if you want to prevent any double-bookings of e.g. appointments, schedules, meetings, etc.

Then You would be sure to catch the error when the user try to validate the appointment.

Then You would need to find a way to signal clients when appointments have changed. But You are on the BEAM and You have pubsub.

When your core logic is ready, it would be time to implement UI