🔗tl;dr

Presumably you're only looking to make this switch if you're already using Fastmail for your email. With that out of the way, you can just use Fastmail's migration tool. Or, if you want to do it a slightly more complicated way, read on.

🔗The Old, Good Internet

The internet used to be built on interoperable standards. The process was not always uniform or clean, but it produced some pretty great standards: TCP/IP, DNS, HTTP, email, and CalDAV to name a few. All of these standards are alive today, and the great thing about them is that there are many different interoperable clients and servers (or senders and receivers, if you prefer) for each of these. If I make an email client that works with your email server, then it works with anyone's email server (typically – there are always exceptions).

This was what Cory Doctorow calls "the old, good internet" in his Enshitternet blog post and, later, in his book Enshittification: Why Everything Suddenly Got Worse and What to Do About It. Today's internet doesn't much resemble the old, good internet even if the underpinnings are largely the same. But some things have survived, like email (though plagued by spam) and CalDAV. CalDAV is how I can keep my calendar server and switch calendar programs – like moving from Apple Calendar to Fantastical – or keep my calendar program and switch calendar servers – like moving from Google Calendar to iCloud.

🔗Switching from iCloud to Fastmail Calendar

For now, I'm only moving away from the iCloud calendar server, not the Apple Calendar client. I will likely explore alternatives in a future post.

I've used iCloud calendar since it was a thing. I think I used Google Calendar for a while before that, but that history is lost to time. It's the easy choice for anyone using an iPhone today, or a Mac at the time I first switched.

iCloud calendar being CalDAV-compatible means I can switch the calendar server to Fastmail calendar and my calendar program can still work with it – even Apple Calendar! To make the switch, I did the following on macOS:

  1. Export the calendar to an ICS file.
  2. Import the ICS file into a new calendar in Fastmail Calendar.
  3. Repeat steps 1–2 for each calendar.
  4. Configure your calendar client on various devices to use Fastmail Calendar.

Afterward, once you've made very sure all your data is now in Fastmail, you probably want to delete the data from iCloud. I recommend waiting at least a week or so to ensure you've got everything moved over! Just disable the iCloud calendars on your devices so you don't start modifying both sets of calendars, leading to hard-to-reconcile differences.

This took me a few minutes per calendar. Between me and my wife we had about 12 calendars (don't ask), so in total it took about an hour plus a bit more time to configure all the devices to point to Fastmail instead of iCloud.

🔗Trade-offs: iCloud vs. Fastmail

Mostly, there's no difference.

🔗Same-ish

  • Arbitrary number of calendars.
  • Calendars have custom names and colors.
  • Shared calendars.
  • Event reminders.
  • Travel time.

However, there are a few things using Apple's servers with Apple's clients gives you that you may miss if you switch.

🔗iCloud-only (not comprehensive)

  • In-calendar client notifications when changes are made by another user.
  • Event attachments (I didn't really use this anyway).

That's a pretty short list.

🔗Boring Infrastructure

The fact that I could do this at all is the point. My calendar data isn't held hostage by Apple or anyone else. If Fastmail ever disappoints me, I can export and move again. That's the promise of the old, good internet: your data, your choice of tools. It's nice when that promise actually holds up – boring is exactly what infrastructure should be.