code: protected static void dateFormat(String pattern, String... attributeNames) {
          ModelDelegate.dateFormat(modelClass(), pattern, attributeNames);
      }
docs: Registers date format for specified attributes. This format will be used to convert between
  Date -> String -> java.sql.Date when using the appropriate getters and setters.
  
  <p>For example:
  <blockquote><pre>
  public class Person extends Model {
  static {
  dateFormat("MM/dd/yyyy", "dob");
  }
  }
  
  Person p = new Person();
  // will convert String -> java.sql.Date
  p.setDate("dob", "02/29/2000");
  // will convert Date -> String, if dob value in model is of type Date
  String str = p.getString("dob");
  
  // will convert Date -> String
  p.setString("dob", new Date());
  // will convert String -> java.sql.Date, if dob value in model is of type String
  Date date = p.getDate("dob");
  </pre></blockquote>
  
  @param pattern pattern to use for conversion
  @param attributeNames attribute names