This tutorial demonstrates how to set up custom calendar notifications using Postman and Twilio, allowing users to receive SMS notifications for special events such as national fruit holidays. The process involves creating a Postman collection, adding example requests for data storage, mocking the API on Postman servers, setting up an SMS notification with Twilio, running the collection locally in Postman, scheduling a monitor to run on Postman servers, and finalizing the setup by verifying that the code is working properly. The tutorial requires users to have a personal phone number, a free Twilio account, and a free Postman account, as well as basic knowledge of Postman and JavaScript.