n8n Workflow: GPT-6 Google Calendar Reminders, Reschedule & Confirm

Never Miss a Google Calendar Confirmation Again—Hourly Reminders, AI Reply Understanding, and Smart Reschedules

This n8n workflow automatically sends Google Calendar meeting reminders via Gmail, monitors guest responses in Google Sheets, and uses OpenAI (GPT-6) to classify replies so it can confirm, reschedule, or cancel—with alerts to you in Telegram.

What this workflow does

• Runs hourly to load configuration such as calendar ID, time zone, working hours, and reminder timing rules.
• Fetches upcoming events within the reminder window and checks a Google Sheets “Reminders” log to determine whether each attendee needs a first reminder, a follow-up nudge, or an at-risk alert.
• Sends reminder/nudge emails to external attendees using Gmail—keeping nudges in the same thread when applicable.
• Notifies you via Telegram when someone is unconfirmed and at risk, and records all actions (including relevant message/thread IDs) back to Google Sheets.
• Monitors ongoing reminder threads by reading active entries from Google Sheets, pulling the corresponding Gmail threads, and detecting new guest messages not yet processed.
• Uses OpenAI to interpret guest replies: determines intent (confirm, reschedule, cancel, question, or other), detects language, summarizes for the owner, and extracts any requested new time.
• Handles rescheduling automatically or interactively by checking Google Calendar free/busy against working hours and notice rules, then either moving the event or proposing available time slots.

Use cases

• Ensure leads confirm meetings on time with automated Gmail reminders and follow-ups.
• Reduce no-shows by triggering Telegram alerts when guests remain unconfirmed.
• Turn “Can we move it?” guest messages into structured reschedule actions using GPT-6.

Technical details

• n8n workflow logic: if, set, code, filter, switch
• Integrations: Gmail (email reminders + thread handling), Google Calendar (events + free/busy + updates), Google Sheets (Reminders log + processed thread tracking), OpenAI (GPT-6 classification/summaries/time extraction), Telegram (at-risk notifications)