code: public long subtract(long instant, int value) {
          if (value == Integer.MIN_VALUE) {
              return subtract(instant, (long) value);
          }
          return add(instant, -value);
      }
docs: Subtracts a duration value (which may be negative) from the instant.
  
  @param instant  the milliseconds from 1970-01-01T00:00:00Z to subtract from
  @param value  the value to subtract, in the units of the field
  @return the updated milliseconds
  @since 1.1