{"product_id":"n8n-workflow-backfill-canceled-appointments-with-google-calendar-whatsapp","title":"n8n Workflow: Backfill Canceled Appointments with Google Calendar + WhatsApp","description":"\u003ch3\u003eBackfill canceled appointments automatically with Google Calendar + WhatsApp\u003c\/h3\u003e\n\u003cp\u003eThis n8n workflow detects canceled or no-show appointments in your \u003cstrong\u003eGoogle Calendar\u003c\/strong\u003e, matches the newly freed time slots to your \u003cstrong\u003eGoogle Sheets waitlist\u003c\/strong\u003e, and (optionally) sends \u003cstrong\u003eWhatsApp offers\u003c\/strong\u003e—all while logging every offer back to Sheets.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRuns every 15 minutes\u003c\/strong\u003e on a schedule to keep backfilling timely.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFetches upcoming Google Calendar events\u003c\/strong\u003e within a configured lookahead window, including \u003cem\u003edeleted\/cancelled\u003c\/em\u003e events.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReads your Google Sheets\u003c\/strong\u003e \u003cstrong\u003eBookings\u003c\/strong\u003e and \u003cstrong\u003eWaitlist\u003c\/strong\u003e tabs to understand what’s booked and who’s waiting.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompares calendar events vs. Bookings\u003c\/strong\u003e to identify freed slots from:\n    \u003cul\u003e\n      \u003cli\u003ecancelled\/deleted appointments\u003c\/li\u003e\n      \u003cli\u003ebookings marked as \u003cem\u003eno-show\u003c\/em\u003e\n\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEnforces a minimum notice window\u003c\/strong\u003e by excluding slots that fall inside your configured cutoff period.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMatches freed slots to waitlist entries\u003c\/strong\u003e in join order, with optional filtering by requested \u003cstrong\u003eservice\u003c\/strong\u003e and\/or \u003cstrong\u003epractitioner\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrafts one or more offers per slot\u003c\/strong\u003e for eligible waitlist entries.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOptional WhatsApp sending + logging:\u003c\/strong\u003e if enabled, sends each offer via WhatsApp and appends offer details to an \u003cstrong\u003eOffer log\u003c\/strong\u003e sheet; otherwise runs as a \u003cstrong\u003edry run\u003c\/strong\u003e without sending.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eReduce downtime after last-minute cancellations by immediately offering openings to people on your waitlist.\u003c\/li\u003e\n  \u003cli\u003eBackfill no-shows by turning missed appointments into opportunities for waitlisted clients.\u003c\/li\u003e\n  \u003cli\u003eSupport multiple services\/practitioners while only notifying the right waitlist segment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eScheduler\u003c\/strong\u003e: runs every 15 minutes.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrations\u003c\/strong\u003e: Google Calendar, Google Sheets, and WhatsApp Business Cloud.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWorkflow logic\u003c\/strong\u003e uses: \u003cem\u003eif, set, code, no op, split out\u003c\/em\u003e, and \u003cem\u003eWhatsApp\u003c\/em\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSetup\u003c\/strong\u003e requires: Calendar ID, spreadsheet ID + required tabs\/columns (Bookings, Waitlist, Offer log), and WhatsApp Phone Number ID (with waitlist numbers in WhatsApp-compatible format).\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":46029415710899,"sku":"N8N-19596","price":44.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/CYEpQWRL9iG-JvFXBtyhJ_aAxp19aP.png?v=1789463525","url":"https:\/\/buyflowscripts.com\/products\/n8n-workflow-backfill-canceled-appointments-with-google-calendar-whatsapp","provider":"N8N Commerce","version":"1.0","type":"link"}