Datetime host variables are supported only for ILE COBOL for iSeries.

Date, time, and timestamp fields are brought into your program only if you specify the *DATETIME option of the CRTCBLPGM CVTOPT parameter, or the DATETIME option of the PROCESS statement. Without one of these options, these fields become FILLER items.
Date, time, and timestamp fields are brought in as fixed-length character fields.