Apple iCloud (CalDAV)

iCloud Calendar, the calendar behind Apple Calendar on iPhone, iPad and Mac, connects over CalDAV. This works on Windows and Linux as well as macOS.

Create an App-Specific Password

iCloud does not accept your Apple ID password in other apps. It needs an app-specific password, which requires two-factor authentication on your Apple ID.

1. Sign in at account.apple.com.
2. Go to Sign-In and Security → App-Specific Passwords.
3. Create a password, name it "memrynote", and copy it.

Connect

In Settings → Calendar → CalDAV, pick Apple iCloud, enter your Apple ID email and the app-specific password, and press Test connection.

If iCloud rejects the password, memrynote says so and reminds you that the Apple ID password does not work here. That is the most common cause.

When It Stops Syncing

Resetting your Apple ID password revokes every app-specific password. The account then shows Reconnect with that explanation. Create a new app-specific password and reconnect.