PUT and INPUT

[mahender1]

In the code below everything is working fine.

DATA NEW;
NUMDT=20081990;
CHRDT=PUT(NUMDT,8.);
SASDT=INPUT(CHRDT,DDMMYY8.);
FORMAT SASDT DATE9.;
RUN;

but in the below code:

DATA NEW;
NUMDT=20081990;
CHRDT=PUT(NUMDT,date7.);
SASDT=INPUT(CHRDT,DDMMYY8.);
FORMAT SASDT DATE9.;
RUN;

it was not working fine.

can anyone please when exactly should i need to mention in put-format as date7.

[novinosrin]

DATA NEW1;
NUMDT=20081990;
temp=input(PUT(NUMDT,8.),ddmmyy8.);
CHRDT=put(temp,date7.);
SASDT=INPUT(CHRDT,date7.);
FORMAT SASDT DATE9.;
RUN;

The temp variable is just reading ease and eyesight

[Astounding · Accepted solution]

When should you use the DATE7 format?  Never.

The DATE7 format uses two-digit years, which introduces pitfalls and complications that are a major headache.  For example, try @novinosrin 's program, but instead of using 20081990, use 20081915 as your original date.  You will end up with a different date than you started with.

[Tom]

The variable NUMDT in your programs does NOT contain a date. It has the value 20,081,990.  The date value for the '20AUG1990'd is 11,189 since it is that number of days after '01JAN1960'd.  In the second program you are treating it as if it was a date. But over 20 million days is almost 55,000 years.