The DATFMT keyword specifies the internal date format, and optionally the separator character, for any of these items of type Date: standalone field; data-structure subfield; prototyped parameter; or return value on a prototype or procedure-interface definition. This keyword will be automatically generated for an externally described data structure subfield of type Date and determined at compile time.
If DATFMT is not specified, the Date field will have the date format and separator as specified by the DATFMT keyword on the control specification, if present. If none is specified on the control specification, then it will have *ISO format.
See Table 33 for valid formats and separators. For more information on internal formats, see Internal and External Formats.