DATTIM(a b)

Sometimes you may not be able to avoid moving dates between 4-digit and 2-digit years, and you know that inaccuracy will result based on the default windowing algorithm that ILE COBOL uses. You can use the DATTIM process statement option to change the default date window. DATTIM takes the form:
  DATTIM(a b)
where a is the 4-digit base century and b is the 2-digit base year.