n8n WhatsApp Appointment Reminder Workflow (Google Calendar + Gmail)

Send WhatsApp appointment reminders automatically—24 hours and 2 hours before—and manage patient replies in your calendar

This n8n workflow checks your Google Calendar every 15 minutes and sends WhatsApp appointment reminders to patients 24 hours and 2 hours before their events. It also logs each reminder to prevent duplicates and routes patient responses to either calendar confirmation or your front desk via Gmail.

What this workflow does

• Runs every 15 minutes: pulls upcoming Google Calendar events for the next 25 hours.
• Avoids duplicate reminders: reads previously sent reminders from an n8n Data Table named appointment_reminders.
• Sends reminders at the right time: selects only events due for a 24-hour or 2-hour reminder.
• Extracts patient phone numbers: reads the patient phone number from the event description.
• Sends a WhatsApp template message: includes quick-reply buttons for Confirm and Reschedule, then records the send in the Data Table (columns include eventId, type, phone, sentAt).
• Handles inbound WhatsApp replies: when a message arrives, it parses the button payload or text to detect intent.
• Confirms appointments: if the patient confirms, the workflow updates the Google Calendar event color and sends a WhatsApp confirmation.
• Reschedules / routes other requests: if the patient requests rescheduling (or sends any other message), it emails the front desk via Gmail and includes the calendar link for reschedules; it sends a WhatsApp acknowledgement for reschedule requests.

Use cases

• Dental/clinic scheduling: reduce no-shows with WhatsApp reminders timed to patient appointments.
• Front-desk triage: automatically notify staff in Gmail when patients choose reschedule.
• Operational reliability: guarantee “only one reminder per event” using the n8n Data Table log.

Technical details

• Integrations: Google Calendar, WhatsApp Cloud API (Meta), Gmail
• n8n building blocks: schedule, data table, code, switch, WhatsApp trigger/handling, and a sticky note for guidance