migrator-to-fastmail-calendar

This migrates Google calendars to Fastmail calendars using a slightly different method from their official sync tool.

Notably this preserves the colour of the individual calendar events which is useful if you've colour-coded them in the past. Fastmail's default migration does not do this.

These are quite messy scripts that were written for a one-off process, so... bear that in mind.

Details

• You need caldav 0.10.0 (older versions won't work!)
• You need google-api-python-client 2.65.0, google-auth-httplib2 0.1.0, google-auth-oauthlib 0.7.1.

Use FASTMAIL_USERNAME and FASTMAIL_PASSWORD in the environment to login to Fastmail.

The credentials should be your email address and your app-specific password which is configured in the "Third-party apps" section of the Fastmail settings panel.

For the Google part, you need to register an app in the Cloud Console. For me this link is here: https://console.cloud.google.com/apis/credentials?project=api-project-846782172465&pli=1

Google provides a credentials.json you can download.

Running export_gcal.py will create a file out.json which is a reasonably-faithful copy of the main Google calendar for the account.

Having done this, you run write_to_fastmail.py to map and write the events into your Fastmail calendar.

Note that as of late 2022 the Google CalDAV interface that uses the Python caldav library does NOT work.

You can use clear_calendar.py to delete all items from the calendar if something goes wrong with the migration.

Likewise, list_calendar.py can be used as a debugging tool to ensure that iCal events are getting created properly within Fastmail.