st: Re: dates in stata

["Martin Weiss" <martin.weiss1@gmx.de>]

<>

Lisa may also profit from Nick`s 
http://www.stata-journal.com/sjpdf.html?articlenum=pr0006

The essential point here is that you read in your dates as strings, and when 
you fire up -sort- it sorts like you would sort, say, surnames: according to 
the alphabet.

Once you have applied the string-to-date functions recommended in this 
thread and described under -help dates_and_times, mark(str2num)-, dates are 
defined as number of days from 1/1/1960. This allows you to sort a numeric 
variable, although it is still displayed as 1/8/2008, according to the 
format you apply to the new variable...

HTH
Martin
_______________________
----- Original Message ----- 
From: <lschoele@rumms.uni-mannheim.de>
To: <statalist@hsphsun2.harvard.edu>
Sent: Tuesday, March 31, 2009 10:44 PM
Subject: st: dates in stata


> Hello Statalist,
>
> I am using Stata for event study. I entered all my variables and 
> observations.
> Regarding my variable "date" I have a problem. When I use "sort date", 
> stata  sorts the date shown above:date
> 01 April 2002
> 01 April 2003
> 01 April 2004
> 01 April 2005
> 01 April 2008
> 01 August 2000
> 01 August 2001
> 01 August 2002
> 01 August 2003
> 01 August 2005
> 01 August 2006
> 01 August 2007
> 01 August 2008
> 01 December 2000
> 01 December 2003
> 01 December 2004
> 01 December 2005
> 01 December 2006
> 01 February 2000
> 01 February 2001
> 01 February 2002
> 01 February 2005
> 01 February 2006
> 01 February 2007
> 01 February 2008
> 01 July 2002
> 01 July 2003
> 01 July 2004
> 01 July 2005
> 01 July 2008
> 01 June 2000
> 01 June 2001
> 01 June 2004
> 01 June 2005
> 01 June 2006
> 01 June 2007
> 01 March 2000
> 01 March 2001
> 01 March 2002
> 01 March 2004
> 01 March 2005
> 01 March 2006
> 01 March 2007
> 01 May 2000
> 01 May 2001
>
> I can tell that stata sorts by the first letter of the month. Do I  have 
> to use a special format for the date? I also tried the format  01.04.2002, 
> but that gives me the same sortation shown above.
>
> Can anyone help me?
>
> Best regards
> Lisa
>
>
>
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