This n8n workflow automates the process of making phone call reminders for upcoming appointments by integrating Google Calendar and Retell AI. It runs daily at a specified time (default 9 AM), retrieves upcoming events within the next 12 hours, extracts key details such as the attendee’s name, phone number, reason, and start/end times from event descriptions, and then automatically calls the recipient with a personalized message. The setup includes configuring Retell API credentials, Google Calendar access, and customizing parameters like the caller number and agent ID. This workflow is ideal for service providers, clinics, or businesses aiming to streamline appointment reminders, reduce no-shows, and improve customer communication at scale.