code: function isValidDate(dateString, dateFormat, returnDateFormat) {
      if(moment(dateString, dateFormat).format(dateFormat) !== dateString) {
          return false;
      }
      if(!moment(dateString, dateFormat).isValid()) {
          return false;
      }
      if(returnDateFormat) {
          return moment(dateString, dateFormat).format(returnDateFormat);
      }
      return true;
  }
docs: Checks the date format along with valid date and convert to the expected format.
  @method isValidDate
  @param {String} dateString The date value to validate.
  @param {String} dateFormat The expected format of the date value.
  @param {String} [returnDateFormat] The expected date format after conversion as the return value.