如下code应该可以，good luck!

data companies;
        length name $20;
        format IPOTime date9.;
        name = "Apple"; IPOTime = "20MAR1995"d; output;
        name = "Nike"; IPOTime = "15MAY1998"d; output;
        name = "New Balance"; IPOTime = "14JUL2004"d; output;
run;

proc sql;
        select round(("31DEC2015"d-IPOTime)/365.25, 0.1) as Years from companies;
quit;

感谢！！很有用！！