topic Choose specific date in a week based on a date variable in SAS Programming

Choose specific date in a week based on a date variable

TheNovice — Wed, 25 Sep 2019 17:49:52 GMT

Hi,
Is there a way to pick a specific date of the given week depending on the date.

If I have records as:

Name Date
AD Sept 11
DF Sept 16

I want to pick be able to pick the Wednesday of the week and report it. Output would look like:

Name Date Week_date
AD Sept 12 Sep 11
DF Sept 16 Sep 18

I know i can just define the ranges in a data step but I wanted to know if there way a different way to do this... The week would be Sun - Sat

Thanks

Re: Choose specific date in a week based on a date variable

Kurt_Bremser — Wed, 25 Sep 2019 17:52:17 GMT

Without complete dates (years!), you can't do that.

Re: Choose specific date in a week based on a date variable

TheNovice — Wed, 25 Sep 2019 17:54:46 GMT

Sorry for the shoddy post Kurt...

Yes I will have the full date with year in there.

Re: Choose specific date in a week based on a date variable

Kurt_Bremser — Wed, 25 Sep 2019 18:21:20 GMT

The weekday() function yields a number between 1 and 7 that specifies the day in the week (1 = Sunday, 7 = Saturday).

This can be used in a rather simple formula:

data want;
format date wednesday weekdatx.;
do date = today() - 7 to today() + 7;
  wednesday = date + 4 - weekday(date);
  output;
end;
run;

proc print data=want noobs;
run;

Result:

date	                        wednesday
Wednesday, 18 September 2019	Wednesday, 18 September 2019
Thursday, 19 September 2019	Wednesday, 18 September 2019
Friday, 20 September 2019	Wednesday, 18 September 2019
Saturday, 21 September 2019	Wednesday, 18 September 2019
Sunday, 22 September 2019	Wednesday, 25 September 2019
Monday, 23 September 2019	Wednesday, 25 September 2019
Tuesday, 24 September 2019	Wednesday, 25 September 2019
Wednesday, 25 September 2019	Wednesday, 25 September 2019
Thursday, 26 September 2019	Wednesday, 25 September 2019
Friday, 27 September 2019	Wednesday, 25 September 2019
Saturday, 28 September 2019	Wednesday, 25 September 2019
Sunday, 29 September 2019	Wednesday, 2 October 2019
Monday, 30 September 2019	Wednesday, 2 October 2019
Tuesday, 1 October 2019	        Wednesday, 2 October 2019
Wednesday, 2 October 2019	Wednesday, 2 October 2019

Re: Choose specific date in a week based on a date variable

Reeza — Wed, 25 Sep 2019 18:38:01 GMT

I'd recommend INTNX() instead.

wednesday = intnx('week', date, 0, 'b') + 3;

The third parameter, the interval, is set to 0 to stay on the same week.

The 'b' aligns it to the beginning of the week, Sunday.

+3 adds 3 days to get it to Wednesday.

This will give the Wednesday of the week, regardless if it's before or after the date.

Re: Choose specific date in a week based on a date variable

TheNovice — Thu, 24 Oct 2019 14:16:45 GMT

Thank you!

Re: Choose specific date in a week based on a date variable

TheNovice — Thu, 24 Oct 2019 14:18:33 GMT

Thanks Reeza, I will try this today. Apologies for the delay. Got pulled onto another task.