How to set up Calendars in iCal

• Run the Apple iCal/Calendar application
• In the menu, select iCal/Calendar → Preferences
• go to tab Accounts
• Click on the + button to create a new account

  

• Choose Add CalDav Account...

  

• Choose Account Type: Manual
• Type your User Name, Password and Server Address [domain.tld]

  

• Next step you need Verify Certificate in Safari browser
• Open Safari and type your domain.tld
• Choose Show Certificate

  

• Choose domain.tld Certificate Authority
• Choose Trust

  

• Choose Always trust