about weekdatew.

[tianerhu]

data CCA;
b = '2Jan1583'd;
run;
proc print data = CCA;
format  b weekdate31.;
run;

tianerhu_0-1629330182074.png

why it is 'NOV'  ?

[tarheel13]

It's not? 

I ran your code and this is what I get in SAS ODA.

Obs	b
1	Sunday, January 2, 1583

[ballardw]

---

@tarheel13 wrote:

It's not? 

I ran your code and this is what I get in SAS ODA.

Obs	b
1	Sunday, January 2, 1583

---

Same with SAS 9.4.4

[tianerhu]

I am sorry . the year is not 1583 , is 1582 , the following is the revised code :

data CCA;
b = '1Jan1582'd;
run;
proc print data = CCA;
format  b weekdate31.;
run;

tianerhu_0-1629334228318.png

[tarheel13]

Okay. I see the same as you. But why are you using a date from the 1500s? 

[tianerhu]

I just want to try . Thank you for your help.

[tarheel13]

Okay. If you use different years like 1982 or 2003, it won't show 'NOV' at the beginning.

[tianerhu]

yes, you are right.
From 1582.1.1---1582.1.9, it displays the wrong value .

[tarheel13]

Well, the good news is I feel like it is pretty unlikely that you would ever work with date values from the 1500s loll.

[tianerhu]

yes, i agree with you.

[ballardw · Accepted solution]

---

@tianerhu wrote:

I am sorry . the year is not 1583 , is 1582 , the following is the revised code :

data CCA;
b = '1Jan1582'd;
run;
proc print data = CCA;
format  b weekdate31.;
run;

tianerhu_0-1629334228318.png

---

From the documentation on dates:

SAS can perform calculations on dates ranging from A.D. November 1582 to A.D. 19,900.

In other words, none of the functions such as determining the day of week are really guaranteed to work before Nov 1582 reliably.

Try this for some interesting results in Jan 1582.

data CCA;
 do b = '1Jan1582'd to '15Nov1582'd ;
   output;
 end;
run;
proc print data = CCA;
format  b weekdate31.;
run;

[tianerhu]

Thank you for your help.