durweek returns number of 7 day periods between 2 dates rounded to 2 decimals

Arguments 

start date as numeric sas date
end date as numeric sas date

e.g. noweeks = durweek(sdate,edate);

*calculates number of 7 day periods between 2 dates;
function durweek(startdt,enddt);
if enddt > startdt then ndy =enddt-startdt+
1;
else ndy =enddt-startdt;
duration = round(ndy/
7,0.01);
return (duration);
endsub;

data _null_;
sdate=
'01jul2001'd;
edate=
'11jul2001'd;
noweeks=durweek(sdate,edate);
put 'number of weeks ' noweeks;
run;


number of weeks 1.57