Sync ICS Webcal Feeds to Google Calendar (n8n Workflow)

Sync ICS / Webcal feeds into Google Calendar—automatically

This n8n workflow automatically mirrors events from an ICS or webcal feed into a Google Calendar, running on a configurable schedule (every 15 minutes by default). It creates missing events and can optionally delete events that no longer appear in the feed.

What this workflow does

• Runs on a schedule (default: every 15 minutes, configurable via a schedule trigger).
• Loads sync settings, including:
  • icsUrl (the ICS/webcal feed URL)
  • calendarId (destination Google Calendar, e.g., primary)
  • syncDaysPast / syncDaysFuture (time window)
  • defaultTimeZone (timezone defaults)
  • deletion toggle (whether to remove outdated mirrored events)
  • eventIdPrefix (used to identify mirrored events)
• Downloads and parses the ICS feed via HTTP, breaking it into individual event occurrences within the configured past/future window and generating deterministic Google Calendar event IDs.
• Fetches existing Google Calendar events within the same time window.
• Compares feed occurrences vs. calendar events (only events whose IDs start with eventIdPrefix are considered).
• Creates missing events in Google Calendar and, if enabled, deletes mirrored events that are no longer present in the ICS feed.

Use cases

• Keep a Google Calendar updated from a recurring events ICS/webcal source (e.g., community calendars, published schedules, venue calendars).
• Maintain consistency between an upstream calendar feed and a destination calendar without manual imports.
• Run “source of truth” synchronization with optional cleanup of events that disappear from the feed.

Technical details

• Google Calendar OAuth2 credentials in both Google Calendar nodes (ensure the account can access the target calendar).
• HTTP download + ICS parsing to generate deterministic event IDs for reliable mirroring.
• Workflow logic uses nodes such as if, set, code, no op, merge, and switch to compare, create, and optionally delete events.