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Re: st: Formatting of dates


From   "Svend Juul" <SJ@SOCI.AU.DK>
To   <statalist@hsphsun2.harvard.edu>
Subject   Re: st: Formatting of dates
Date   Fri, 9 Sep 2005 14:01:50 +0200

I. Mosca wrote:

we have an entry that looks like the following:
1-1-2002 00:00:00
It is a string variable str19 %19s.

We'd like to transform it into a numerical/date format, but the
information we want to keep is only the year.
How can we do that?
-----------

Looking at your date format it seems that the year precedes the first
blank in the string. I create two observations, identify the position of
the first blank character with strpos(), and use that in the substr()
function.

    clear
    input str19 datetime
    "1-1-2002 00:00:00"
    "10-12-1998 13:32:17"
    end

    gen x = strpos(datetime," ")
    gen year = substr(datetime, x-4, 4)

In Stata 8 it is not strpos(), but index():
    gen x = index(datetime," ")

Hope this helps
Svend

__________________________________________

Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000  Aarhus C, Denmark
Phone: +45 8942 6090
Home:  +45 8693 7796
Email: sj@soci.au.dk
__________________________________________

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