topic Re: Datetime in SAS Programming

Datetime first day of year in macro variable

Pandu2 — Thu, 13 Jan 2022 09:27:11 GMT

Hi All,
I hope everyone is doing good.
I need a datetime value for the 1st day of a year, which should look like this.
2022-01-01T00:00:00.000Z
By considering the above datetime only the year needs to be changed whenever the new year comes. The date and month should remain same i.e 01-01.
Example:
2023-01-01T00:00:00.000Z
The datetime value must be in a macro variable.

Any help would be greatly appreciated.
Thanks.

Re: Datetime

andreas_lds — Thu, 13 Jan 2022 06:27:39 GMT

Depending on the purpose of the macro variable it is often better not to store a formatted date, time or datetime value, but the unformatted original. The formatted value is most likely completely useless, when used to filter data. And with a normal datetime you can use intnx to shift the value one year forward.

By considering the above datetime only the year needs to be changed whenever the new year comes

So whenever new data arrives, which is yearly, the year should be increased. But how are you storing the date between sessions? How does the program know that it is the second time new data arrived, and the constant "2022-01-01T00:00:00.000Z" must increased by two?

Maybe this helps, please note that i don't know the name of the datetime format displaying the datetime in the expected form.

data _null_;
   date = intnx('year', today(), 1, 'b');
   dt = dhms(date, 0, 0, 0);
   call symputx('next_year', put(dt, datetime.));
run;

Or, if you want to work with strings:

%macro demo;
   %local start next_year;
   %let start = 2022-01-01T00:00:00.000Z;
   
   %let year = %substr(&start, 1, 4);
   %let year = %eval(&year + 1);
   %let next_year = &year.%substr(&start, 5);
   %put &=next_year;
%mend;

%demo;

Re: Datetime

Pandu2 — Thu, 13 Jan 2022 06:41:33 GMT

Based upon the current date it should know when to change the year but not the date and month i.e 01-01.

Re: Datetime

Pandu2 — Thu, 13 Jan 2022 06:48:22 GMT

May I know the usage of looping here. Is it possible to achieve the required solution using current date or system date. By using current datetime the year must change whenever new year arrives and the rest should be same i.e 01-01T00:00:00.000Z

Re: Datetime

andreas_lds — Thu, 13 Jan 2022 07:08:56 GMT

@Pandu2 wrote:
Based upon the current date it should know when to change the year but not the date and month i.e 01-01.

So, based on the current year, you need year+1? This is exactly what the data step i posted does. The only thing you need to do is finding an appropriate format.

Re: Datetime

Kurt_Bremser — Thu, 13 Jan 2022 08:47:11 GMT

%let macrovar = %sysfunc(intnx(dtyear,%sysfunc(datetime()),0,b));

will give you the zero second of the current year as a raw value, which is usually better in macro variables. Formatted macro variables are only needed for display purposes.

Edit: replaced the TODAY function with DATETIME

Re: Datetime

Pandu2 — Thu, 13 Jan 2022 07:17:52 GMT

It just gave me 0 value. The reason I want it to be in macro variable is I use that macro variable in a url.

Re: Datetime

andreas_lds — Thu, 13 Jan 2022 07:17:57 GMT

Thought that today() returns a date, not a datetime, but maybe i am not up-to-date.

Re: Datetime

Pandu2 — Thu, 13 Jan 2022 07:20:05 GMT

Yes but, will your code change the year when a new year comes.

Re: Datetime

Kurt_Bremser — Thu, 13 Jan 2022 08:48:25 GMT

Correct. Somewhere between setting up the post in my brain and typing it into the forum DATETIME changed to TODAY 😉

Re: Datetime

Kurt_Bremser — Thu, 13 Jan 2022 08:49:28 GMT

See correction. Has to be DATETIME in the inner %SYSFUNC.

To get the correct format, just add it as a second parameter to %SYSFUNC.

Re: Datetime

Pandu2 — Thu, 13 Jan 2022 09:52:14 GMT

Thanks for the code but does your code work whenever the new year arrives?.

Re: Datetime

Kurt_Bremser — Thu, 13 Jan 2022 09:56:49 GMT

See the documentation (Maxim 1):

DATETIME Function

Re: Datetime first day of year in macro variable

Ksharp — Thu, 13 Jan 2022 11:42:24 GMT

%let datetime= %sysfunc(date(),year4.)-01-01T00:00:00.000Z ;

%put &=datetime. ;