The RECOVER command with DATE(mm/dd/yy), or the REPORT command with FROMDATE(mm/dd/yy) or TODATE(mm/dd/yy), was issued before 1 January 2000.
DFSMShsm uses the date to determine (for RECOVER) which backup version should be recovered, or (for REPORT) which range of records should be reported.
After 1999, the date must always be specified as yyyy/mm/dd.
DFSMShsm