Converting datetime to SAS date format

[Walternate]

Hi,

I have a SAS dataset with a date variable that is in datetime format. I need to have it in SAS date format to run some code, but I'm not sure how to convert a variable from datetime format to SAS date format.

Any help is much appreciated.

Thanks!

[CTorres · Accepted solution]

Create a new date variable with the DATEPART function:

date=datepart(datetime);

A SAS datetime is the number of seconds since (or until) Jan 1, 1960.  A SAS date is the number of days since (or until) Jan 1, 1960.  The DATEPART function converts the datetime to a date value.

Or if you simply need to format it for display purposes, or as a class variable in a SAS proc, use the DTDATE9. format to display just the date portion.

(Editor's note: more example and explanation in this blog post.)

[Walternate]

Thanks for your response!

I actually need it to be in SAS date format (ie, the number of days from Jan 01 1960).

[Reeza]

Is your original variable a character or numeric variable? Sample data is always helpful.

[Walternate]

The original variable is in datetime20 format.

[CTorres]

If the original variable is in datetime20. format it means the type of this variable is datetime. You cannot give this variable a date. format. You need to change the type from datetim to date to be able to apply the date format.

[CTorres]

It is not the format what makes a variable date or datetime It's the contents: if it contains the number of days since Jan 01 1960 then it is a date but if it contains the number of seconds it is a datetime.

For this reason you can not have a date variable with datetime format and viceversa (a datetime variable with date format). You need to change the contents of a variable to change the type from date to datetime or viceversa

Regards

[Reeza]

You can have a datetime variable with a date format...

DTDATE9.

can you post the proc contents from your dataset please.

[CTorres]

Reeza you are right! Thanks.

You can display the datepart of a datetime variable with the DTDATE9. format but this does not change the type of the variable.

[Walternate]

It says that the variable is numeric with a format and informat of datetime20.

[Reeza]

Then CTorres solution should work. If its not, post the code and log.

Usually errors like this are caused by 1) Character rather than numeric 2)typos 3) Not overwriting a variable or dataset properly.

[SASKiwi]

If you want to permanently convert a datetime column to date and store it as such assign date informat and format at the same time as converting it:

datevar = datepart(datevar);

format datevar date9.;

informat datevar date9.;

[Walternate]

Hi all,

Thanks for your help, but I think I'm not communicating my issue well enough so let me try to be clearer.

I have a column that is currently akin to:

Date1

21DEC198700:00:00

22DEC198800:00:00

08AUG198700:00:00

etc.

All I want is to convert this to SAS date, so that I will have a new column:

Date2

39876 (or however many days Dec. 21, 1987 is from Jan. 1, 1960)

39877

39801

I know the numbers aren't correct, but basically I just want my DDMMMYYYYTT:TT:TT format converted to the sas date "number of days since Jan. 1, 1960" format.

Thanks!

[Tom]

Not sure about the missing colon between your date and time parts, but if your variable is a NUMBER instead of a character string then DATEPART() will convert it. If you want it to display as a date by default then attach the format you want to it.

45   data want ;

46    set have ;

47    put date1= datetime20. @25 date1 comma15. ;

48    date1 = datepart(date1);

49    put date1= date9. @25 date1 comma15. ;

50    format date1 date9.;

51    informat date1 date9.;

52   run;

date1=21DEC1987:00:00:00    882,662,400

date1=21DEC1987                  10,216

date1=22DEC1988:00:00:00    914,371,200

date1=22DEC1988                  10,583

date1=08AUG1987:00:00:00    870,998,400

date1=08AUG1987                  10,081

NOTE: There were 3 observations read from the data set WORK.HAVE.

NOTE: The data set WORK.WANT has 3 observations and 1 variables.

[Tom]

That is exactly what the DATEPART() function does. It converts number of seconds into number of days.  Basically it divides by 24*60*60.