code: public static Expression millisToZone(Expression expression, String timeZoneName, String format) {
          if (format == null || format.isEmpty()) {
              return x("MILLIS_TO_ZONE(" + expression.toString() + ", \"" + timeZoneName + "\")");
          }
          return x("MILLIS_TO_ZONE(" + expression.toString() + ", \"" + timeZoneName + "\"" +
                  ", \"" + format + "\")");
      }
docs: Returned expression results in a convertion of the UNIX time stamp to a string in the named time zone.