How to add iCloud calendar ?

These simple steps will show you how to add and synchronise iCloud calendar.

Requirements

Since June 15th 2017 all third-pary applications require an app-specific password for connection to iCloud due to Apple security restrictions. See Apple Support.

In order for this to work two steps need to be done:

  1. Setup two-factor authentication for your Apple ID.
  2. Generate an app-specific password.

1. Setup two-factor authentication

For detailed instructions see Apple Support.

If you're using iOS 10.3 or later:

  1. Go to Settings > [your name] > Password & Security.
  2. Tap Turn on Two-Factor Authentication.
  3. Tap Continue.
  4. Enter and verify your trusted phone number.

If you're using iOS 10.2 or earlier:

  1. Go to Settings > iCloud.
  2. Tap your Apple ID > Password & Security.
  3. Tap Turn on Two-Factor Authentication.
  4. Tap Continue.
  5. Enter and verify your trusted phone number.

If you're using Mac with OS X El Capitan or later:

  1. Go to Apple () menu > System Preferences > iCloud > Account Details.
  2. Click Security.
  3. Click Turn on Two-Factor Authentication.

2. Generate an app-specific password

For detailed instructions see Apple Support.

Instructions:

  1. Sign in to your Apple ID account page.
  2. In the Security section, click Generate Password below App-Specific Passwords.
  3. Follow the steps on your screen.
  4. After you generate your app-specific password, enter or paste it into the OneCalendar password field.