code: public void setMillis(long instant) {
          switch (iRoundingMode) {
              case ROUND_NONE:
                  break;
              case ROUND_FLOOR:
                  instant = iRoundingField.roundFloor(instant);
                  break;
              case ROUND_CEILING:
                  instant = iRoundingField.roundCeiling(instant);
                  break;
              case ROUND_HALF_FLOOR:
                  instant = iRoundingField.roundHalfFloor(instant);
                  break;
              case ROUND_HALF_CEILING:
                  instant = iRoundingField.roundHalfCeiling(instant);
                  break;
              case ROUND_HALF_EVEN:
                  instant = iRoundingField.roundHalfEven(instant);
                  break;
          }
          super.setMillis(instant);
      }
docs: Set the milliseconds of the datetime.
  <p>
  All changes to the millisecond field occurs via this method.
  
  @param instant  the milliseconds since 1970-01-01T00:00:00Z to set the
  datetime to