code: public static String changeFormatAndTimeZoneToDefaultUtcFormat(
              String dateFormat, String zoneId, String dateString) {
          return JMOptional.getOptional(zoneId)
                  .map(zId -> getTimeAsDefaultUtcFormat(
                          changeTimestampToLong(dateFormat,
                                  dateString, zoneId)))
                  .orElseGet(() -> changeFormatAndTimeZoneToDefaultUtcFormat(
                          dateFormat, dateString));
      }
docs: Change format and time zone to default utc format string.
  
  @param dateFormat the date format
  @param zoneId     the zone id
  @param dateString the date string
  @return the string