Get last day the week

[kz134]

Hi 

I have a dataset that is split by weeks. example:

Date	value
201801	a
201802	b
201803	c

The date indicates the week number of the year. The date is in character format. How do convert the date to get the last day of that week instead?

Want:

Date	value	Date2
201801	a	2018-01-06
201802	b	2018-01-13
201803	c	2018-01-20

[Reeza · Accepted solution]

1. Add W to get in a week format that SAS understands, ie 2018W01, 2018W02, 2018W03

2. Convert to a SAS date using INPUT and the WEEKV informat

3. Increment to the end of the week.

For the WEEKV rules:

https://documentation.sas.com/?cdcId=pgmsascdc&cdcVersion=9.4_3.4&docsetId=leforinforref&docsetTarge...

*create sample data to test - please provide this in the future;
data have;
input date $ value $;
cards;
201801 a
201802 b
201803 c
;
run;


data want;
set have;

	/*1 Add W*/
	dateW = catt(substr(date, 1, 4), 'W', substr(date, 5, 2));

	/*2 Convert to SAS Date*/
	z = input(dateW, weekv.);

	/*3. Find end of week*/
	x = intnx('week', z, 0, 'e');

	/*4 doing it in one step*/
	x2 = intnx('week', input(catt(substr(date, 1, 4), 'W', substr(date, 5, 2)), weekv.), 0, 'e');

	*Format appearance;
	format x x2 date9.;
run;

---

@kz134 wrote:

Hi 

I have a dataset that is split by weeks. example:

Date	value
201801	a
201802	b
201803	c

The date indicates the week number of the year. The date is in character format. How do convert the date to get the last day of that week instead?

Want:

Date	value	Date2
201801	a	2018-01-06
201802	b	2018-01-13
201803	c	2018-01-20

---

[kz134]

worked well. thank you 

[Astounding]

How do you define "last day of the week" ?

Why should the first week end on January 6, not January 7?