Manual method
Download calendars as portable iCalendar (.ics) files.
- On a computer, open Google Calendar → Settings → Import & export.
- Under Export, choose Export and save the ZIP.
- Extract the ZIP and keep every calendar’s .ics file.
- For one calendar, open its Settings and sharing page and use Export calendar.
Coverage and limitations: The mobile app cannot perform this export. You need the calendar permission to make changes and manage sharing; an organization may restrict exports. Subscribed calendars are not automatically owned exportable history.
Size and time to allow
Illustrative small / central / large case: 0.001 / 0.02 / 0.2 GB (decimal GB). These are planning assumptions, not a measured average per person. 20 MB models many years of events and descriptive text. Linked meeting recordings and documents are separate files, not included merely because a URL is present.
Preparation: Usually a short interactive export; budget 1–5 minutes of setup and packaging as an estimate. Network transfer for the model size is only seconds.
For the central 0.02 GB example, network transfer alone is approximately:
| Connection | Estimated transfer |
|---|---|
| 10 Mbps | 23 seconds |
| 50 Mbps | 5 seconds |
| 100 Mbps | 2 seconds |
Assumes 70% sustained use of the stated connection. Provider throttling, many small files, retries, local extraction and copying add time. For online backup use your upload speed. These are not estimates of the provider’s preparation queue. See calculation and large-file advice.
Store and verify the archive
The example is small enough for an encrypted USB key, external drive or private cloud folder. Choose a second independent copy as well; a single USB key is easy to lose and a sync folder alone can propagate deletion.
Create google_calendar/YYYY-MM-DD/originals/, preserve the untouched download, and extract a separate working copy when needed. Allow extra free space for archive plus extraction; compressed text can expand far beyond twice its size. Record account/scope, export date, date coverage and missing items in a local README without passwords.
Open a copy in a disposable calendar, inspect recurring events, time zones and earliest/latest dates; avoid importing into your live calendar and creating duplicates. Reopen a sample from the second copy before deleting or replacing any source. Storage choices and verification.
Sources and review
Public documentation was reviewed on 27 October 2026. No signed-in export or restoration was performed. Account options and availability can change; follow the current provider instructions.