I have an issue on SAS 9.4, using proc export. The dataset to be exported, has a date field which is not exporting correctly.   For all records where the value of the date field in the original file is <= 12/31/1959, then the value of that field in the exported XLSX file, is 12/31/1959.   I have changed the values in that column by hand before exporting to check, and found that 12/31/1959 is the boundary line between exporting correctly and not.   To make sure the problem wasn't (say) corrupted data, I also tried adding 20 years to each value in the date field using INTX, before exporting, so that all values were > 12-31-1959, and all the new values were exported to .XLSX correctly.   The syntax of the export is  Proc Export data=work.dataset outfile  = "/mydir/outfile.xlsx" dbms=xlsx replace label; run;   Incidentally, this issue occurs when the field in the exported file is in DDMMYY10. format (which fulfills a business rule), but does *NOT* occur when the field is in DATE9. format. For DATE9, correctly exported values of 01/01/1959 in the SAS dataset,  become '1-Jan-59' in the exported .XLSX file.   Is this is known issue, or is there a workaround for it?   ... View more