Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide

Converting dates

You can convert between a two-digit date (d1) with the pattern YYMMDD and a four-digit date (d2) with the pattern YYYYMMDD using assignments:

d2 = DAYSTODATE(DAYS(d1,'YYMMDD',w), 'YYYYMMDD');
d1 = DAYSTODATE(DAYS(d2,'YYYYMMDD'), 'YYMMDD' ,w);
Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide