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Re: st: wrong datetime results with clock() -- sometimes


From   Austin Nichols <[email protected]>
To   [email protected]
Subject   Re: st: wrong datetime results with clock() -- sometimes
Date   Fri, 5 Jul 2013 15:28:02 -0400

Rebecca Pope <[email protected]>:
Try a double.

clear all
input str21 timestr
" 2/8/2011 9:50:51 PM"
"2/12/2011 4:15:40 PM"
"2/11/2011 3:26:12 PM"
"5/15/2011 9:46:41 AM"
"5/20/2011 8:32:28 PM"
" 2/7/2011 2:15:40 PM"
"5/25/2011 7:07:57 PM"
" 5/9/2011 3:00:42 PM"
"5/22/2011 3:24:57 PM"
" 5/9/2011 7:09:46 PM"
end
gen dt=clock(timestr,"MDYhms")
gen double dt2=clock(timestr,"MDYhms")
format dt dt2 %tc
li

On Fri, Jul 5, 2013 at 3:05 PM, Rebecca Pope <[email protected]> wrote:
> Hello,
> I am trying to convert a variable with datetime observations currently
> stored as string to a numeric format. Here is a sample of my data
> after issuing these command:
>
> gen datetime = clock(timestr,"MDYhms")
> format datetime %tc
>
> . list timestr datetime in 1/10, noobs clean
>                  timestr             datetime
>      2/8/2011 9:50:51 PM   08feb2011 21:50:37
>     2/12/2011 4:15:40 PM   12feb2011 16:14:48
>     2/11/2011 3:26:12 PM   11feb2011 15:27:08
>     5/15/2011 9:46:41 AM   15may2011 09:46:59
>     5/20/2011 8:32:28 PM   20may2011 20:31:39
>      2/7/2011 2:15:40 PM   07feb2011 14:16:37
>     5/25/2011 7:07:57 PM   25may2011 19:08:51
>      5/9/2011 3:00:42 PM   09may2011 15:01:44
>     5/22/2011 3:24:57 PM   22may2011 15:25:01
>      5/9/2011 7:09:46 PM   09may2011 19:10:46
>
> As you can see, the converted values are a few seconds off from the
> time stored in the string variable.
>
> I don't think that this is a Stata problem per se because if I convert
> a single observation, the correct time is displayed:
> . di %tc clock("2/8/2011 9:50:51 PM", "MDYhms")
> 08feb2011 21:50:51
>
> That said, I'm not the first person to encounter this
> (http://www.stata.com/statalist/archive/2011-10/msg00687.html).
> However, I don't see that a solution/reason was ever provided.
>
> My best guess in the face of this was a hidden character in the
> variable. I checked for this with the following:
> replace timestr = subinstr(" "+timestr+" "," ","-",.) in 1/10
>                    timestr
>      -2/8/2011-9:50:51-PM-
>     -2/12/2011-4:15:40-PM-
>     -2/11/2011-3:26:12-PM-
>     -5/15/2011-9:46:41-AM-
>     -5/20/2011-8:32:28-PM-
>      -2/7/2011-2:15:40-PM-
>     -5/25/2011-7:07:57-PM-
>      -5/9/2011-3:00:42-PM-
>     -5/22/2011-3:24:57-PM-
>      -5/9/2011-7:09:46-PM-
>
> As you can see, the hyphens are right next to the text, so I don't
> think there is anything lurking at the beginning or end of the text
> that isn't displaying.
>
> Does anyone have other suggestions?
>
> Thanks,
> Rebecca
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