code: public static String changeFormatAndTimeZoneToOffsetDateTime(
              String dateFormat, String dateString) {
          return getOffsetDateTime(changeTimestampToLong(dateFormat, dateString))
                  .toString();
      }
docs: Change format and time zone to offset date time string.
  
  @param dateFormat the date format
  @param dateString the date string
  @return the string