SAS does not let me assign 29-Feb-4000 as a valid date. Tt looks like it is defining years divisible by 4000 as not leap years. I think this is incorrect. I tried 29-FEB-8000 and that generates an error too. 28 a_date = '29FEB4000'd; output; ____________ 77 ERROR: Invalid date/time/datetime constant '29FEB4000'd. ERROR 77-185: Invalid number conversion on '29FEB4000'd. ... View more