Count the Number of Days of the Week Between Two Dates

[griffinh]

Wow--thank you Reeza for such a comprehensive answer. I will work through this and update you on the result. The version of SAS Enterprise Guide that I am using is more of a GUI/low code environment so I have not written any custom programs. I've already learned a lot--syntax especially--from the snippet of code to recreate the two rows of data. Thank you again, I am diving into this today.

[Reeza]

You likely also need to account for Spring Break, so you can add your custom holidays within my logic in the first step - basically add in the extra University closures you need to add. 

[s_lassen]

Not accounting for holidays, you can do it like this:

data want;                                         
  set have;                                        
  array week(*) Sunday--Saturday;                  
  days=0;                                          
  do _N_=1 to dim(week);                           
    if week(_N_) then                              
      days+intck(cats('week.',_N_),bannerStartDate-1,bannerEndDate);                
    end;                                           
run;

The INTCK function counts the number of Sundays passed with first parameter=WEEK.1, Mondays with WEEK.2, etc. We have to subtract one from the first date in case the period starts on a relevant day.