The user date special words (UDATE, *DATE, UMONTH, *MONTH, UDAY, *DAY, UYEAR, *YEAR) allow the programmer to supply a date for the program at run time. The user date special words access the job date that is specified in the job description. The user dates can be written out at output time; UDATE and *DATE can be written out using the Y edit code in the format specified by the control specification.
See Rules for User Date for more information.