data a;
interval='month';
start='14FEB2013'd;
end='13MAR2013'd;
months_default=intck(interval, start, end);
months_discrete=intck(interval, start, end, 'd');
months_continuous=intck(interval, start, end, 'c');
output;
end='14MAR2013'd;
months_default=intck(interval, start, end);
months_discrete=intck(interval, start, end, 'd');
months_continuous=intck(interval, start, end, 'c');
output;
start='31JAN2013'd;
end='01FEB2013'd;
months_default=intck(interval, start, end);
months_discrete=intck(interval, start, end, 'd');
months_continuous=intck(interval, start, end, 'c');
output;
format start end date9.;
run;
proc print data=a;
run;