You can always use Java's DateFormat
API for achieving this. Here is the code snippet that will help you to achieve whatever task you are looking for.
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
Date date = dateFormat.parse("2017-04-26T20:55:00.000Z");//You will get date object relative to server/client timezone wherever it is parsed
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); //If you need time just put specific format for time like 'HH:mm:ss'
String dateStr = formatter.format(date);
You will get date object from which you can use it whichever way you would like to display using date formatter to format again.