title: Get JSON from a public Google Calendar
body: <p>How can I get a <code>JSON</code> with the events of a <strong>public</strong> Google Calendar? I have it's <code>ID</code> but no acess to it. I don't want to change its events, nor log in. </p>
  
  <p>I would like get a <code>JSON</code> from it to sync with my <code>PHP</code>/<code>MySql</code> database.</p>
  
  <p>Tried <code>https://www.googleapis.com/calendar/v3/calendars/{calendarId}</code></p>
  
  <p>but got login error:</p>
  
  <pre><code>{
   "error": {
    "errors": [
     {
      "domain": "global",
      "reason": "required",
      "message": "Login Required",
      "locationType": "header",
      "location": "Authorization"
     }
    ],
    "code": 401,
    "message": "Login Required"
   }
  }
  </code></pre>