topic Re: How to calculate time difference between two string datetime in SAS Programming

How to calculate time difference between two string datetime

Sally_Caffrey — Sun, 11 Sep 2022 15:12:11 GMT

Hi,

I have two columns like below, STDTC and ENDTC in string format ($100). I want to calculate the time difference between them. I tried to convert stdtc to datetime format but failed bacause only one row with time and other rows are date. Seems it cannot make this column to be both date and datetime. How to calculte ?

STDTC ENDTC

2022-01-03 2022-01-03

2022-03-22 2022-05-02

2022-06-02T10:30 2022-06-04

Thanks for your help!

Re: How to calculate time difference between two string datetime

PaigeMiller — Sun, 11 Sep 2022 16:37:16 GMT

You have to create new numeric variables from the character variables in order to work with these.

You show five dates, and one date/time ... exactly what result do you want here anyway?

Maybe this?

data have;
input STDTC $16. ENDTC :$16.;
cards;
2022-01-03                2022-01-03
2022-03-22                2022-05-02
2022-06-02T10:30          2022-06-04 
;
data want;
     set have;
     stdtn=input(stdtc,B8601DT.);
     endtn=input(endtc,B8601DT.);
     delta=endtn-stdtn;
     format delta time16.;
run;

Re: How to calculate time difference between two string datetime

Sally_Caffrey — Tue, 13 Sep 2022 15:38:21 GMT

That's exactly I want. Thanks! BTW, when I try to create numeric variables from stdtc by using input(stdtc, E8601DT.), the log reports "Invalid argument to function INPUT".

The SAS help shows that B8601DT. writes datetime values in the ISO 8601 basic notation yyyymmddThhmmssffffff. , while E8601DT. in extended notation yyyy-mm-ddThh:mm:ss.ffffff.

Why E8601DT. reports the note ?

Re: How to calculate time difference between two string datetime

PaigeMiller — Tue, 13 Sep 2022 16:14:50 GMT

This isn't a very good answer ... but B8601DT seems happy when the value is just a date and no time component, while E8601DT seems to only work when there is a time component. However, I don't see where the documentation says that.

Re: How to calculate time difference between two string datetime

Sally_Caffrey — Wed, 14 Sep 2022 01:48:21 GMT

Thanks a lot!

Re: How to calculate time difference between two string datetime

ballardw — Wed, 14 Sep 2022 16:33:52 GMT

@PaigeMiller wrote:

This isn't a very good answer ... but B8601DT seems happy when the value is just a date and no time component, while E8601DT seems to only work when there is a time component. However, I don't see where the documentation says that.

The difference in the documentation is that B8601dt includes:

If the hour, minute, or second values are omitted, SAS uses a value of 0 for the hour, minute, or second.

but E8601dt does not have a similar piece in the description.

Re: How to calculate time difference between two string datetime

PaigeMiller — Wed, 14 Sep 2022 16:40:10 GMT

@ballardw wrote:

@PaigeMiller wrote:

This isn't a very good answer ... but B8601DT seems happy when the value is just a date and no time component, while E8601DT seems to only work when there is a time component. However, I don't see where the documentation says that.

The difference in the documentation is that B8601dt includes:

If the hour, minute, or second values are omitted, SAS uses a value of 0 for the hour, minute, or second.

but E8601dt does not have a similar piece in the description.

That answers the question!!