Help using Base SAS procedures

How to change 0001-01-01 as date format?

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Contributor hua
Contributor
Posts: 66

How to change 0001-01-01 as date format?

Hi, 

 

I used the code:

%let start_date=01Jan0001;
%let end_date=31Dec2013;
data Date;
do date="&start_date"d to "&end_date"d;
output;
end;
format date date9.;
run;

data YMD;
set Date;
Year=year(date);
month=month(date);
day=day(date);
drop date;
run;

 

But, SAS don't recognize the date before 1600-01-01.

Does anyone know how to solve this?

 

Thanks!

Super User
Super User
Posts: 7,039

Re: How to change 0001-01-01 as date format?

Why do you want to store invalid dates?

Are you using them as some type of special missing value?  If so then pick a different date that can be stored in a SAS date variable.

Otherwise just work with your dates as either strings or three separate year, month and day variables.

Contributor hua
Contributor
Posts: 66

Re: How to change 0001-01-01 as date format?

Not the missing value. I'm dealing with GCM data. The time format is the days after 0001-01-01. I want to check if the data I use are the coresponding date. Smiley Happy Thanks
Regular Contributor
Posts: 161

Re: How to change 0001-01-01 as date format?

Not sure I'm clear on the exact issue you mentioned....

 

" I want to check if the data I use are the coresponding date."

 

Would you be able to elaborate with an example of the challenge you have?

Kannan Deivasigamani
Respected Advisor
Posts: 4,920

Re: How to change 0001-01-01 as date format?

It becomes very messy to deal with pre-18th century dates, before the adoption of our regular calendar. SAS will not do that for you.

 

About SAS Date, Time, and Datetime values

 

 

If you really need them, use year, month, day values and good luck Smiley Happy

PG
Contributor hua
Contributor
Posts: 66

Re: How to change 0001-01-01 as date format?

Thanks.
Yes, SAS could only recognize the dates after 1600.
I did this in excel. Smiley Happy
Respected Advisor
Posts: 4,920

Re: How to change 0001-01-01 as date format?

This is what I would try. If the foreign date system considers 01-01-0001 as day zero then foreignDate-584388 should give you the corresponding SAS date. If 01-01-0001 is day one then that expression should be foreignDate-584389.

 

-584388 is '01JAN1600'd - '01JAN3200'd

PG
Super User
Posts: 11,343

Re: How to change 0001-01-01 as date format?


hua wrote:
Thanks.
Yes, SAS could only recognize the dates after 1600.
I did this in excel. Smiley Happy

You need to double check what Excel may have done. It doesn't recognize dates by default before 1900, at least on my install. I suspect you ended up with a TEXT value in Excel not an actual date. See what happens if you change the cell format in Excell to display a different date format.

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