count days between two variables

[Xinhui]

Hi,

I have two variables :rdq and datadate,

I wanna calculate the days between two dates, 

I use the folllowing code:

data f_f;
set f_l2;
days=intck('day', datadate, rdq);
run;

but the code not work all the days are '.'. 

Could you please help me correct the code?

Thanks in advance. 

[Patrick]

Your code as such looks valid so the issue must be in the data.

Your two variables datadate and rdq must contain SAS Date values for your code to work. 

A SAS Date value is the count of days since 1/1/1960.

It's not really possible to say much more without access to your data. If you can attach your SAS table (sas7bdat) file with a few rows to your question. You could also execute below code and post the result here. That would also tell us more about your real data.

proc print data=f_l2(obs=1 keep=datadate rdq);
  format datadate rdq date9.;
run;

proc print data=f_l2(obs=1 keep=datadate rdq);
  format datadate rdq datetime21.;
run;

proc print data=f_l2(obs=1 keep=datadate rdq);
  format datadate rdq 32.;
run;

proc contents data=f_l2(keep=datadate rdq);
run;quit;

[Xinhui]

The SAS System

Obs rdq datadate1

*********

*********

---

The SAS System

Obs rdq datadate1

19AUG1960:14:30:28

19AUG1960:14:28:51

---

The SAS System

Obs rdq datadate1

20010628

20010531

---

The SAS System

The CONTENTS Procedure

Data Set NameObservationsMember TypeVariablesEngineIndexesCreatedObservation LengthLast ModifiedDeleted ObservationsProtectionCompressedData Set TypeSortedLabel Data Representation Encoding 

WORK.F_L2	19811
DATA	2
V9	0
2022-01-02 18:19:42	280
2022-01-02 18:19:42	0
	NO
	NO
WINDOWS_64
euc-cn Simplified Chinese (EUC)

Engine/Host Dependent InformationData Set Page SizeNumber of Data Set PagesFirst Data PageMax Obs per PageObs in First Data PageNumber of Data Set RepairsExtendObsCounterFilenameRelease CreatedHost Created

65536
86
1
233
217
0
YES
C:\Users\lenovo\AppData\Local\Temp\SAS Temporary Files\_TD16424_DESKTOP-U6HBCL9_\f_l2.sas7bdat
9.0401M2
X64_8HOME

Alphabetic List of Variables and Attributes# Variable Type Len Format Informat126

datadate	Num	8	BEST12.	BEST32.
rdq	Num	8	BEST12.	BEST32.

[Patrick · Accepted solution]

This made it clear. You have numerical variables with values that express a date as yyyymmdd but that are not a SAS date value.

We need to convert these numbers to a SAS date value in order to do something useful with it.

data f_l2;
  datadate=20010628;
  rdq=20010531;
run;

data test;
  set f_l2;
  /* convert number in form yyyymmdd to SAS Date value (count of days since 1/1/1960) */
  datadate_SASDate  =input(put(datadate,8.),yymmdd8.);
  rdq_SASDate       =input(put(rdq,8.),yymmdd8.);

  /* apply format to SAS Date values so they print as human readable dates and not just the count of days */
  /* a format does not change the internal value but just how the values get printed */
  format datadate_SASDate rdq_SASDate date9.;

  /* calculation options */
  days_1=intck('day', datadate_SASDate, rdq_SASDate);
  days_2=intck('day', input(put(datadate,8.),yymmdd8.), input(put(rdq,8.),yymmdd8.));

  /* and because a SAS Date value is just a count of days we now can use a simple substraction */
  days_1b=rdq_SASDate-datadate_SASDate;
  days_2b=input(put(rdq,8.),yymmdd8.) - input(put(datadate,8.),yymmdd8.);

run;

[Xinhui]

Thank you for your help. It is very detail and well explained. 

Thanks soooo much! I learned from it.