topic Assigning Weeks in New SAS User

Assigning Weeks

jnivi — Mon, 20 Mar 2023 23:09:22 GMT

Hi there,

I have a fairly large dataset (data=have)with dates that spans from April 5, 2021 to December 31, 2022.

I know the SAS date function usually assigns the week number based on the start of the year. However, I was wondering if there was another way to automatically assign a week number to each record in my dataset where 05Apr2021 to 11Apr2021 would be assigned week 1 (not week 0 ), 12Apr2021 to 17Apr2021 would be assigned week 2, and so forth.

Obs ID Date Week

1 1001 05APR2021 1

2 1002 19 APR2021 3

3 2040 01JAN2022

4 7680 08APR2021 2

5 5432 30DEC2022

Thank you!!

Re: Assigning Weeks

Kurt_Bremser — Mon, 20 Mar 2023 22:58:14 GMT

proc sql noprint;
select min(date) into :begin
from have;
quit;

data want;
set have;
week = intck(`week`,&begin.,date,'c') + 1;
run;

Re: Assigning Weeks

AMSAS — Wed, 22 Mar 2023 15:55:41 GMT

Although the code @Kurt_Bremser has supplied works for the example data provided. You also need to be aware that it ONLY works assuming your input data earliest observation has date="05APR2021"d

If you were to run this code against another dataset that which has a different value earliest value for date, e.g. 01APR2021 then week 1 is going to be 01APR2021- 07APR2021.

If you want have consistent behavior where week 1 is always 05APR2021-11APR2021 then you are going to want to remove the PROC SQL step and hard code your starting date (&begin)

INTCK Function

data have ;
	format date date7. ;
	do i=3 to 100 by 3 ;
		date="04APR2021"d+i  ;
		output have ;
	end ;
run ;

proc sort data=have ;
	by date ;
run ;

data want;
	set have;
	week=intck("week","05APR2021"d,date,'c') + 1;
run;