Month-Year Do Loop

[Go210]

Hi Sas experts,

I am missing something in my code that enables me to write a do loop to iterate by month & year.

I have two dates stored in two different variables "Start_Date" and "End_Date" and I want to expand these dates by Month & Year as opposed to expanding every day in between.

The issue is my start date in the second do loop where it starts fine but doesn't start the next year correctly. But I am unsure how to modify this to make it work.

Any help would be greatly appreciated.

This is what I have in terms of code:

data want;
set have;

do year=year(Start_Date) to year(End_Date);

do month= month(Start_Date) to 12;
date =mdy(month,1,year);
format date Date9.;
output;
end;

end;

run;

Output is:

Var A	Start_Date	End_Date	Var B	year	month	date
101	7/01/2014	1/01/2030	50003	2014	7	1-Jul-14
101	7/01/2014	1/01/2030	50003	2014	8	1-Aug-14
101	7/01/2014	1/01/2030	50003	2014	9	1-Sep-14
101	7/01/2014	1/01/2030	50003	2014	10	1-Oct-14
101	7/01/2014	1/01/2030	50003	2014	11	1-Nov-14
101	7/01/2014	1/01/2030	50003	2014	12	1-Dec-14
101	7/01/2014	1/01/2030	50003	2015	7	1-Jul-15
101	7/01/2014	1/01/2030	50003	2015	8	1-Aug-15
101	7/01/2014	1/01/2030	50003	2015	9	1-Sep-15
101	7/01/2014	1/01/2030	50003	2015	10	1-Oct-15
101	7/01/2014	1/01/2030	50003	2015	11	1-Nov-15
101	7/01/2014	1/01/2030	50003	2015	12	1-Dec-15
101	7/01/2014	1/01/2030	50003	2016	7	1-Jul-16
….
1643	2/01/2015	1/01/2030	20083	2015	2	1-Feb-15
1643	2/01/2015	1/01/2030	20083	2015	3	1-Mar-15
1643	2/01/2015	1/01/2030	20083	2015	4	1-Apr-15
1643	2/01/2015	1/01/2030	20083	2015	5	1-May-15
1643	2/01/2015	1/01/2030	20083	2015	6	1-Jun-15
1643	2/01/2015	1/01/2030	20083	2015	7	1-Jul-15
1643	2/01/2015	1/01/2030	20083	2015	8	1-Aug-15
1643	2/01/2015	1/01/2030	20083	2015	9	1-Sep-15
1643	2/01/2015	1/01/2030	20083	2015	10	1-Oct-15
1643	2/01/2015	1/01/2030	20083	2015	11	1-Nov-15
1643	2/01/2015	1/01/2030	20083	2015	12	1-Dec-15
1643	2/01/2015	1/01/2030	20083	2016	2	1-Feb-16
1643	2/01/2015	1/01/2030	20083	2016	3	1-Mar-16

Result Should be:

Var A	Start_Date	End_Date	Var B	year	month	date
101	7/01/2014	1/01/2030	50003	2014	7	1-Jul-14
101	7/01/2014	1/01/2030	50003	2014	8	1-Aug-14
101	7/01/2014	1/01/2030	50003	2014	9	1-Sep-14
101	7/01/2014	1/01/2030	50003	2014	10	1-Oct-14
101	7/01/2014	1/01/2030	50003	2014	11	1-Nov-14
101	7/01/2014	1/01/2030	50003	2014	12	1-Dec-14
101	7/01/2014	1/01/2030	50003	2015	1	1-Jan-15
101	7/01/2014	1/01/2030	50003	2015	2	1-Feb-15
101	7/01/2014	1/01/2030	50003	2015	3	1-Mar-15
101	7/01/2014	1/01/2030	50003	2015	4	1-Apr-15
101	7/01/2014	1/01/2030	50003	2015	5	1-May-15
101	7/01/2014	1/01/2030	50003	2015	6	1-Jun-15
101	7/01/2014	1/01/2030	50003	2016	7	1-Jul-15
….
1643	2/01/2015	1/01/2030	20083	2015	2	1-Feb-15
1643	2/01/2015	1/01/2030	20083	2015	3	1-Mar-15
1643	2/01/2015	1/01/2030	20083	2015	4	1-Apr-15
1643	2/01/2015	1/01/2030	20083	2015	5	1-May-15
1643	2/01/2015	1/01/2030	20083	2015	6	1-Jun-15
1643	2/01/2015	1/01/2030	20083	2015	7	1-Jul-15
1643	2/01/2015	1/01/2030	20083	2015	8	1-Aug-15
1643	2/01/2015	1/01/2030	20083	2015	9	1-Sep-15
1643	2/01/2015	1/01/2030	20083	2015	10	1-Oct-15
1643	2/01/2015	1/01/2030	20083	2015	11	1-Nov-15
1643	2/01/2015	1/01/2030	20083	2015	12	1-Dec-15
1643	2/01/2015	1/01/2030	20083	2016	1	1-Jan-16
1643	2/01/2015	1/01/2030	20083	2016	2	1-Feb-16

[PGStats · Accepted solution]

Use functions INTNX and INTCK for date manipulations:

data want;
set have;
date = Start_Date;
do until(date > End_Date);
    month = month(date);
    output;
    date = intnx("MONTH", date, 1, "SAME");
    end;
format date Date9.;
run;

[Go210]

Thanks PGStats! I will read up on those functions.