r - Time difference giving error

Question

I have two time of same date "2015/09/12 00:02:18" and "2015/09/12 23:59:39" .

How to calculate difference between these two time frames?

Answer 1

You can try to convert the strings into POSIXct and simply calculate the difference:

t1 <- "2015/09/12 00:02:18"
t2 <- "2015/09/12 23:59:39"
> as.POSIXct(t2) - as.POSIXct(t1)
#Time difference of 23.95583 hours

Alternatively you may use difftime(), a function used to calculate time differences:

> difftime(t2, t1)
#Time difference of 23.95583 hours

If you don't want to have the text in the output, you can obtain the time difference in hours with

> unclass(difftime(t2, t1, units="hours"))[1]
#[1] 23.95583