Sum anything past 28 day from today

[hk2013]

how would i count distinct ID that are that have appointments after the next  28 days from today

ID         appt_date

1             6/30/2018

1             7/7/2018

1             7/18/2018

1             7/28/2018

1              8/6/2018

1              9/20/2017

2             6/17/2018

2             6/28/2018

2             7/5/2018

2             7/6/2018

want 

ID 1 has 4 appt after 28 days 

ID 2 has 0 appt after 28 days 

[novinosrin · Accepted solution]

I think there are only 3 for ID1, are you sure it;s 4?

data have;
input ID         appt_date :mmddyy10.;
format appt_date mmddyy10.;
cards;
1             6/30/2018
1             7/7/2018
1             7/18/2018
1             7/28/2018
1              8/6/2018
1              9/20/2017
2             6/17/2018
2             6/28/2018
2             7/5/2018
2             7/6/2018
;
proc sql;
create table want as
select id, sum( appt_date>=intnx('days',today(),28)) as count_of_appoints
from have
group by id;
quit;