Converting numeric date variable to string variable

[Barbara Hama]

Dear all,
I am very new to Stata.
I want to convert the numeric date variable "cdint" (type: long, format: %tdD_m_Y) to a string variable.
It currently looks like that: cdint
25 Jan 07
29 Jan 07
13 Jan 07
29 Jan 07
04 Feb 07
24 Jan 07
01 Feb 07
13 Jan 07
26 Jan 07
21 Jan 07
25 Jan 07
13 Jan 07
15 Jan 07
14 Jan 07
12 Jan 07
23 Jan 07
05 Feb 07
27 Jan 07
27 Jan 07
13 Jan 07
12 Jan 07


I tried to destring it and use the date command but Stata always generates missing values.

destring cdint, replace
gen date = date(cdint, "DMY")
(3,176 missing values generated)

[William Lisowski]

Welcome to Statalist.

Stata's "date and time" variables are complicated and there is a lot to learn. If you have not already read the very detailed Chapter 24 (Working with dates and times) of the Stata User's Guide PDF, do so now. If you have, it's time for a refresher. After that, the help datetime documentation will usually be enough to point the way. You can't remember everything; even the most experienced users end up referring to the help datetime documentation or back to the manual for details. But at least you will get a good understanding of the basics and the underlying principles. An investment of time that will be amply repaid.

All Stata manuals are included as PDFs in the Stata installation (since version 11) and are accessible from within Stata - for example, through the PDF Documentation section of Stata's Help menu.

With that said, this problem was that Stata did not recognize "07" as a year, as one of the examples in the output of help datetime describes. The sample code shown below corrects the problem.

. * Example generated by -dataex-. To install: ssc install dataex
. clear

. input str9 cdint

         cdint
  1. "5 Jan 07" 
  2. "29 Jan 07"
  3. "13 Jan 07"
  4. "29 Jan 07"
  5. "04 Feb 07"
  6. "24 Jan 07"
  7. "01 Feb 07"
  8. "13 Jan 07"
  9. "26 Jan 07"
 10. "21 Jan 07"
 11. "25 Jan 07"
 12. "13 Jan 07"
 13. "15 Jan 07"
 14. "14 Jan 07"
 15. "12 Jan 07"
 16. "23 Jan 07"
 17. "05 Feb 07"
 18. "27 Jan 07"
 19. "27 Jan 07"
 20. "13 Jan 07"
 21. "12 Jan 07"
 22. end

. gen date = date(cdint, "DM20Y")

. format date %td

. list, clean

           cdint        date  
  1.    5 Jan 07   05jan2007  
  2.   29 Jan 07   29jan2007  
  3.   13 Jan 07   13jan2007  
  4.   29 Jan 07   29jan2007  
  5.   04 Feb 07   04feb2007  
  6.   24 Jan 07   24jan2007  
  7.   01 Feb 07   01feb2007  
  8.   13 Jan 07   13jan2007  
  9.   26 Jan 07   26jan2007  
 10.   21 Jan 07   21jan2007  
 11.   25 Jan 07   25jan2007  
 12.   13 Jan 07   13jan2007  
 13.   15 Jan 07   15jan2007  
 14.   14 Jan 07   14jan2007  
 15.   12 Jan 07   12jan2007  
 16.   23 Jan 07   23jan2007  
 17.   05 Feb 07   05feb2007  
 18.   27 Jan 07   27jan2007  
 19.   27 Jan 07   27jan2007  
 20.   13 Jan 07   13jan2007  
 21.   12 Jan 07   12jan2007  

.

[Barbara Hama]

Thank you very much, William!
It worked.