title: Unable to find the right iOS DateFormatter in Swift
body: <p>In my app I am getting date string from server like that "2019-12-30 21:25:06" so I am using the formatter like "yyyy-MM-dd HH:mm:ss", Then I want to change the date for mat to "Dec 30, 2019" so I change the format to "MMM dd, yyyy" but it doesn't work. </p>
  
  <p>Here I using "<a href="https://nsdateformatter.com/" rel="nofollow noreferrer">https://nsdateformatter.com/</a>" and using the formatter "yyyy-MM-dd HH:mm:ss" means the date will changed from "2019-12-30 21:25:06" to "2019-12-30 15:55:06", I can't find the reason.</p>
  
  <p>Here I mention my code for date formatter.</p>
  
  <pre><code>let createdDateString:String = "2019-12-30 21:25:06"
  let dateFormatter = DateFormatter()
  dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
  let dateOrder = dateFormatter.date(from: createdDateString)
  dateFormatter.dateFormat = "MMM dd, yyyy"
  let orderDateStr:String = dateFormatter.string(from: dateOrder!)
  dateLbl.text = orderDateStr
  </code></pre>