topic Re: Compute days between dates in SAS Programming

Compute days between dates

RandyStan — Sat, 11 Aug 2018 02:30:32 GMT

Dear All

My data is as follows

ID ID_A Date
1. A 03JAN2010
1. A. 04JAN2010
1. A. 10JAN2010
1. B. 05JAN2010
1. B. 07JAN2010
2. A. 02FEB2010
2. A. 08FEB2210
2. C. 18JAN2010
2 C. 20JAN2010

I want to construct a variable that calculates the Days between the dates
ID ID_A Date DBD_WO_Holidays.
1. A 03JAN2010 1
1. A. 04JAN2010 6
1. A. 10JAN2010. -50000
1. B. 05JAN2010. 2
1. B. 07JAN2010 -50000
2. A. 02FEB2010 6
2. A. 08FEB2210 -50000
2. C. 18JAN2010 2
2 C. 20JAN2010 -50000

The -50000 is just an indicator it is the last date for ID_A

Thanks in advance

Randy

Re: Compute days between dates

hashman — Sat, 11 Aug 2018 04:14:51 GMT

@RandyStan:

You don't say what kind of holidays you have in mind. There're means in SAS to account for them (see the HOLIDAY function), but they have to be specific. With the holiday considerations aside, you just need to include a little mechanism of looking forward:

data have ;                                
  input ID ID_A:$1. Date:date. ;           
  format date date9. ;                     
  cards ;                                  
1  A  03JAN2010                            
1  A  04JAN2010                            
1  A  10JAN2010                            
1  B  05JAN2010                            
1  B  07JAN2010                            
2  A  02FEB2010                            
2  A  08FEB2010                            
2  C  18JAN2010                            
2  C  20JAN2010                            
run ;                                      
                                           
data want (drop = _:) ;                    
  set have ;                               
  by ID ID_A ;                             
  if last.ID_A then DBD = -50000 ;         
  else do ;                                
    p = _n_ + 1 ;                          
    set have (keep=date rename=(date=_d)) point = p ;
    DBD = intck ("day", date, _d) ;        
  end ;                                    
run ;

HTH

Paul D.

p.s. Note that I had to correct your sample input DATE in record #7 from year 2210 to 2010, otherwise your sample output for the prior record makes no sense.

Re: Compute days between dates

Ksharp — Sat, 11 Aug 2018 11:17:19 GMT

data have ;                                
  input ID ID_A:$1. Date:date. ;           
  format date date9. ;                     
  cards ;                                  
1  A  03JAN2010                            
1  A  04JAN2010                            
1  A  10JAN2010                            
1  B  05JAN2010                            
1  B  07JAN2010                            
2  A  02FEB2010                            
2  A  08FEB2010                            
2  C  18JAN2010                            
2  C  20JAN2010                            
;
run ;   
data want; 
 merge have have(rename=(id=_id id_a=_id_a date=_date) firstobs=2);
 if id=_id and id_a=_id_a then  DBD_WO_Holidays=_date-date;
  else  DBD_WO_Holidays=-50000;
  drop _:;
run;