st: How to get 4-digit year number

["Akihito Tokuhara" <akitoku4@hotmail.com>]

Dear all,

I want to strip the dates to get only the 4-digit year number, using the 
code below:

generate qyear=date(dateinc2,"mdy")
format qyear %d        /* This formats the qyear into  12july1987  */
generate byear=yofd(qyear)            /* This strips the 4-digit year number 
from the date */

But if the dates only has 4-digit number, it does not work. Those year 
numbers become missing
values in new variable.

Is there any way to do all in few codes, including other forms of dates 
which are non-missing.

Thanks in advance.

Akihito

_________________________________________________________________
Don�t just search. Find. Check out the new MSN Search! 
http://search.msn.click-url.com/go/onm00200636ave/direct/01/

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/