*HIVAL and *LOVAL move the result type's extreme value:
C MOVE *HIVAL dIso ('9999-12-31')
C MOVE *LOVAL dIso ('0001-01-01')
C MOVE *HIVAL tIso ('24.00.00', end-of-day)
C MOVE *LOVAL tIso ('00.00.00')
C MOVE *HIVAL ts ('9999-12-31-24.00.00.000000')
C MOVE *LOVAL ts ('0001-01-01-00.00.00.000000')
*BLANKS and *ZEROS carry no date or time value and are rejected for a
date/time/timestamp result (TRN1542);
they remain valid for a character or numeric result. *SYS is an INZ keyword
value rather than a data operand and is rejected as a MOVE/MOVEL Factor 2
for every result type (TRN1541).