Choose specific date in a week based on a date variable

[TheNovice]

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

[Kurt_Bremser]

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

[TheNovice]

Sorry for the shoddy post Kurt...

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

[Kurt_Bremser · Accepted solution]

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

[TheNovice]

Thank you!

[Reeza]

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.

[TheNovice]

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