Thanks a lot!
On Fri, Mar 28, 2008 at 6:55 PM, Svend Juul <[email protected]> wrote:
> ippab wrote:
>
> I have two variables, one indicating date and another indicating time
> of the day. For example, date = 03/26/2008 and time = 17:31:30. I am
> wondering how I can combine these two variables into one variable so
> that I can use the new "Datetime" variable for tis.
>
> My understanding is that 'tis' command (for panel data or time series
> analysis) only accepts one variable. Since I have several
> observations for a panel on the same day, I need to make sure both
> date and time are used as the time variable.
>
> =====================================================
>
> In Stata 10 the numeric value of a date variable is the number of days
> since 1 January 1960 , and the numeric value of a time variable is the
> number of milliseconds since midnight. Before adding them, transform the
> date to milliseconds.
>
> . clear
> . set obs 1
> . gen date = mdy(3,26,2008)
> . format date %tdNN/DD/CCYY
> . gen time = hms(17,31,30)
> . format time %tcHH:MM:SS
> . list
> +-----------------------+
> | date time |
> |-----------------------|
> 1. | 03/26/2008 17:31:30 |
> +-----------------------+
>
> . gen double datetime = date*24*60*60*1000 + time
> . format datetime %tcNN/DD/CCYY_HH:MM:SS
> . list
> +---------------------------------------------+
> | date time datetime |
> |---------------------------------------------|
> 1. | 03/26/2008 17:31:30 03/26/2008 17:31:30 |
> +---------------------------------------------+
>
>
> 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, work: +45 8942 6090
> Phone, home: +45 8693 7796
> Fax: +45 8613 1580
> E-mail: [email protected]
> _________________________________________________________
>
>
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>
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