This is the most important module in the course. It explains how the calendar integration actually works — what Tunelark can and can’t see, how sub-calendars and shared calendars behave, and why understanding free vs. busy status matters.

Key concepts covered:

Privacy: Tunelark and your students can only see whether your time is free or busy. No event titles, descriptions, or details are ever visible.

Primary calendar only: Tunelark reads only your primary Google Calendar. Sub-calendars, shared calendars, and calendars from other apps (Apple, Outlook) are not visible to Tunelark — even if you can see them in your Google Calendar view.

Free vs. Busy: Every event has a status. Busy blocks your availability. Free keeps it open. Google defaults to busy, so reminder events can accidentally block your time if you don’t change their status.

Real-time updates: Your calendar syncs instantly. The moment you add a busy event, that time disappears from your Tunelark availability. You don’t need to reserve time exclusively for Tunelark — the system works around your real life.