# ⨳ last week of quarter ⨳

May 19, 2014

A coworker recently asked me how I would identify the last week of a quarter when the date variable is formatted as week.2.

Here’s what I came up with.

data _null_;
do i = 0 to 250;
X_DT=intnx('week.2','01jan2010'd, i);
last_week_of_quarter = (qtr(X_DT) ne qtr(intnx('week.2', x_dt, 1)));
end;
run;


Which flagged the following dates as beginning in the last week of the quarter:

• Monday, December 28, 2009
• Monday, March 29, 2010
• Monday, June 28, 2010
• Monday, September 27, 2010
• Monday, December 27, 2010
• Monday, March 28, 2011
• Monday, June 27, 2011
• Monday, September 26, 2011
• Monday, December 26, 2011
• Monday, March 26, 2012
• Monday, June 25, 2012
• Monday, September 24, 2012
• Monday, December 31, 2012
• Monday, March 25, 2013
• Monday, June 24, 2013
• Monday, September 30, 2013
• Monday, December 30, 2013
• Monday, March 31, 2014
• Monday, June 30, 2014
• Monday, September 29, 2014

That looked good to me. All the flagged weeks we indeed at the end of the quarter.

Then the additional requirement that the X_DT values are set to the end of the week (Sunday), rather than the beginning (Monday). That throws a wench in things.

My initial thought was to simple add the 'e' argument to the initial intnx function. But that didn’t work.

• Sunday, September 30, 2012
• Sunday, March 31, 2013
• Sunday, June 30, 2013

These dates are weeks that end on the last day of the quarter. That’s not quite what he was after.

Adding the 'e' argument to the second intnx function as well seemed to fix things:

• Sunday, March 28, 2010
• Sunday, June 27, 2010
• Sunday, September 26, 2010
• Sunday, December 26, 2010
• Sunday, March 27, 2011
• Sunday, June 26, 2011
• Sunday, September 25, 2011
• Sunday, December 25, 2011
• Sunday, March 25, 2012
• Sunday, June 24, 2012
• Sunday, September 30, 2012
• Sunday, December 30, 2012
• Sunday, March 31, 2013
• Sunday, June 30, 2013
• Sunday, September 29, 2013
• Sunday, December 29, 2013
• Sunday, March 30, 2014
• Sunday, June 29, 2014
• Sunday, September 28, 2014

Which is the list of the last week that ends within a given quarter.

last week of quarter - May 19, 2014 -