Multi-Calendar Conflict Detection Research¶

Research into techniques and tools for identifying scheduling conflicts across multiple calendars (Google Calendar and CalDAV).

What it is¶

A set of methods to aggregate availability data from multiple sources (e.g., family members' calendars) and calculate overlapping "busy" periods to find suitable meeting or event times.

What problem it solves¶

Prevents double-booking and simplifies scheduling in a multi-user or multi-account environment by automating the check for availability across disparate calendar systems.

Where it fits in the stack¶

Knowledge Base / Pattern. It informs the logic used in automation tools like n8n to orchestrate calendar events.

Typical use cases¶

Husband and wife coordinating family events.
Scheduling personal tasks without conflicting with work meetings.
Automated appointment booking agents checking multiple providers.

Strengths¶

Privacy-First: Using Free/Busy APIs allows checking availability without exposing event details (titles, descriptions).
Interoperability: Can combine data from Google Calendar and self-hosted CalDAV servers.

Limitations¶

Latency: Multiple API calls are required to fetch data from different providers.
Complexity: Timezone handling and recurring event expansion must be managed correctly by the logic layer.

When to use it¶

When scheduling requires coordination between two or more independent calendar accounts.
When an AI agent needs to suggest non-conflicting time slots.

When not to use it¶

For simple, single-account scheduling where a native "Check Availability" feature already exists.

Implementation Details¶

Google Calendar Free/Busy API¶

The Google Calendar API provides a freebusy.query method that returns blocks of busy time for one or more calendars.

Example Request (Python):

body = {
  "timeMin": "2026-05-01T00:00:00Z",
  "timeMax": "2026-05-02T00:00:00Z",
  "items": [{"id": "user1@gmail.com"}, {"id": "user2@gmail.com"}]
}
eventsResult = service.freebusy().query(body=body).execute()

The response contains a dictionary of calendars, each with a list of busy periods (start and end times).

Chronos MCP (CalDAV)¶

Chronos MCP supports multi-account management for CalDAV servers (Nextcloud, Fastmail, etc.). It can be used to query multiple calendars simultaneously and aggregate their events for conflict analysis.

Sources / references¶

Contribution Metadata¶

Last reviewed: 2026-04-18
Confidence: high