Try:
=DATEDIF("3/28/1951","6/5/2013","y")
EDIT: Welcome to the forum!
I'm not able to get this function to work correctly at all. here is what i have been trying:
=dateif(B20,B21,"y") no luck returns the #NAME error.
B20 = today()
B21 = 6/25/2022
I also tried entering the actual dates in to the function and still returned nothing.
=dateif("8/26/2014","6/25/2022","y")