@light wrote: I have trouble finding statistical forum though. Dark blue button "Find a Community" --> Analytics (click plus sign) --> SAS Statistical Procedures ... View more

Thank you. That works. ... View more

You could begin by creating a data set with just the leap years.  Using the trick from @Rick_SAS:   data leap_years(keep=year); length date 8; do year=2000 to 2200; /* MISSING when Feb 29 not a valid date */ date=mdy(2,29,year); if not missing(date) then output; end; run; Then you could join/merge or exclude dates from your reference data set based on the years that appear in the results of this program.  See more explanation in my blog post on this: SAS knows it's a leap year; do you? ... View more