01
Current status
Separate roadmap from available product
Google Calendar currently implements only feature-flagged development event creation, normalized reads of DewEngine-confirmed creates, and the command-derived canonical creation event; Microsoft Calendar and every broader Google read, sync, update/delete, availability, recurrence, and watch feature remain planned. A credible alternative claim still requires real-account conformance, operational service levels, security evidence, support, and migration tooling.
02
Capability comparison
Compare operation depth provider by provider
Build a matrix for account types, calendar discovery, free/busy, create, update, cancel, attendees, resources, conferencing, recurrence, webhooks, delta recovery, and provider-specific fields. A route count is not capability proof.
- Google consumer and Workspace accounts
- Microsoft consumer and organizational accounts
- Shared calendars and resources
- Recurring event and sync edge cases
03
Operational comparison
Evaluate the service around the endpoints
Compare data residency, token custody, retention, deletion, webhook delivery, reconnection, incident communication, rate behavior, exports, support, and contractual provider authorization alongside price.
04
Migration design
Keep provider identity available for a reversible move
Map account, calendar, and event identifiers without assuming vendor IDs are portable. Reconnect users through the destination's OAuth application, run a bounded baseline, dual-observe changes, and switch traffic only after parity checks pass.
- Explicit user reauthorization
- Provider ID mapping
- Read-only comparison window
- Rollback and data deletion plan