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datedatetimesasformatinformat

Define date format on the basis of given date in a txt file

I have been provided dates/datetimes in .txt file

For example:

20180422
02122018
2018/04/22
22/04/2018
04-02-2018
2018-04-20 13:05:56

Now, first I do import above .txt file, so it will be in numeric format in sas dataset. For each date I need to automatically define date_format.

Format examples:

yyyymmdd
mmddyyyy
yyyy/mm/dd
dd/mm/yyyy
dd-mm-yyyy
yyyy-mm-dd hh:mm:ss

How do I define the format based on the given date?

Solution

  • In my first step I saved the dates as String then used input(a,anydtdte20.) in the following step to convert them to SAS dates and input(a,ymddttm24.) for datetime; this way all the dates with '/' and'-' will be read as SAS dates.

    Please note that I am using the locale for DMY and in the case of datetime I extract only the date part.

    options DATESTYLE=DMY;
data have;
length a $ 23 ;
input a $;
datalines;
20180422
12022018
2018/04/22
22/04/2018
04-02-2018
2018-04-20T13:05:56
;
run;

data want;
set have;
format date_a date9.;
date_a=input(a,anydtdte20.);
Year_a=year(date_a);
month_a=month(date_a);
day_a=day(date_a);
run;

    Output (Want data set):

    a=20180422 date_a=22APR2018 Year_a=2018 month_a=4 day_a=22
a=12022018 date_a=12FEB2018 Year_a=2018 month_a=2 day_a=12
a=2018/04/22 date_a=22APR2018 Year_a=2018 month_a=4 day_a=22
a=22/04/2018 date_a=22APR2018 Year_a=2018 month_a=4 day_a=22
a=04-02-2018 date_a=04FEB2018 Year_a=2018 month_a=2 day_a=4
a=2018-04-20T13:05:56 date_a=20APR2018 Year_a=2018 month_a=4 day_a=20

    You can find more dynamic date & datetime informats in this SAS Post.

    To take this one step further you can create extra columns/variables for each format you want, datetime handling added here:

    proc sql;
create table dates as 
select
a as Date_String ,
date_a as SAS_Date9 format=date9. ,
date_a as SAS_YYMMDDN8 format=YYMMDDN8. ,
date_a as SAS_DDMMYYN8 format=DDMMYYN8. ,
date_a as SAS_YYMMDDS10 format=YYMMDDS10. ,
date_a as SAS_DDMMYYS10 format=DDMMYYS10. ,
case when LENGTH(a) > 10 then input(a,ymddttm24.) else . end as SAS_Datetime21 format=datetime21. ,
case when LENGTH(a) > 10 then timepart(input(a,ymddttm24.)) else . end as SAS_Time format=time8. 
from work.want;
quit;

    Output:

    SAS_Date9=22APR2018 SAS_YYMMDDN8=20180422 SAS_DDMMYYN8=22042018 SAS_YYMMDDS10=2018/04/22
SAS_DDMMYYS10=22/04/2018 SAS_Datetime21=. SAS_Time=.
SAS_Date9=12FEB2018 SAS_YYMMDDN8=20180212 SAS_DDMMYYN8=12022018 SAS_YYMMDDS10=2018/02/12
SAS_DDMMYYS10=12/02/2018 SAS_Datetime21=. SAS_Time=.
SAS_Date9=22APR2018 SAS_YYMMDDN8=20180422 SAS_DDMMYYN8=22042018 SAS_YYMMDDS10=2018/04/22
SAS_DDMMYYS10=22/04/2018 SAS_Datetime21=. SAS_Time=.
SAS_Date9=22APR2018 SAS_YYMMDDN8=20180422 SAS_DDMMYYN8=22042018 SAS_YYMMDDS10=2018/04/22
SAS_DDMMYYS10=22/04/2018 SAS_Datetime21=. SAS_Time=.
SAS_Date9=04FEB2018 SAS_YYMMDDN8=20180204 SAS_DDMMYYN8=04022018 SAS_YYMMDDS10=2018/02/04
SAS_DDMMYYS10=04/02/2018 SAS_Datetime21=. SAS_Time=.
SAS_Date9=20APR2018 SAS_YYMMDDN8=20180420 SAS_DDMMYYN8=20042018 SAS_YYMMDDS10=2018/04/20
SAS_DDMMYYS10=20/04/2018 SAS_Datetime21=20APR2018:13:05:56 SAS_Time=13:05:56

    Dates