[R] Time Interval calculation using R

[jim holtman]

Seems to work fine for me:

> times <- c("10:12:34", "14:23:15")
> Ptime <- as.POSIXct(strptime(times, "%H:%M:%S"))
>
> Ptime
[1] "2008-10-05 10:12:34 GMT" "2008-10-05 14:23:15 GMT"

> difftime(Ptime[2], Ptime[1], units='min')
Time difference of 250.6833 mins
>

You just have to be careful that all your times are for the same day
since you do not have a 'date' associated with the time.

On Sun, Oct 5, 2008 at 1:25 AM, Gouri Shankar Mishra
<gouri.mishra at gmail.com> wrote:
> Hi
>
> I have two columns of data with time in form of HH:MM:SS - representing
> start time and end time of an activity. I am trying to calculate the time
> difference (duration of the activity).
>
> (1) I first tried
>> difftime(btime, etime, units = "mins")
> This however gave me the error - Error in
> as.POSIXlt.character(as.character(x)) :  character string is not in a
> standard unambiguous format
>
> (2) The above error message indicated some problem in format. So I tried
>> etime1=as.date(etime, %H:%M:%S")
> This gave me the Error: unexpected SPECIAL in "etime1=as.date(etime, %H:%"
>
> I also tried
>>etime1=format(etime, %H:%M:%S")
> But this gave a similar error - unexpected SPECIAL in "etime1=format(etime,
> %H:%"
>
> Any suggestions?
>
> Regards
>
>        [[alternative HTML version deleted]]
>
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-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?