calculate time differnce in a data frame

Question

I have a data frame with two columns for TIME. Time has the formatting H:M:S

dataframe <- 
   TIME1        TIME2
   08:20:05     12:30:05

I want to calculate time difference in "hours" and put it in a column to data frame. I tried this but didn't work.

dataframe$TimeDif <- difftime(dataframe$TIME1, dataframe$TIME2, unit="hours")

This is the error msg I get: Error in as.POSIXlt.character(x, tz, ...) : character string is not in a standard unambiguous format

This is the error msg I get: `Error in as.POSIXlt.character(x, tz, ...) : character string is not in a standard unambiguous format` — daragh, Aug 10 '17 at 06:54
There you go, your variables are character. You need to change it to time. Have you tried searching the internet? This is a very common question (see [here](https://stackoverflow.com/questions/12649641/calculating-time-difference-in-r) for example). Also, you can edit your question to include the error message. Perhaps take a minute and read up on how SO functions. — Roman Luštrik, Aug 10 '17 at 06:56
I searched and tried this hut still did't work: `data$TIME1 <- as.POSIXct(data$TIME1 , format = "%H:%M:%S") data$TIME2 <- as.POSIXct(data$TIME2 , format = "%H:%M:%S") data$TimeDif <- difftime(data$TIME1 , data$TIME2 , unit="hours")` — daragh, Aug 10 '17 at 07:05
It needs to be datetime or date. AFAIK there is no time object in R. Please study the documentation (or e.g. [here](https://www.stat.berkeley.edu/~s133/dates.html)). — Roman Luštrik, Aug 10 '17 at 07:07

score 0 · Answer 1 · answered Aug 10 '17 at 07:46

0

please try the code below:

 difftime(strptime(dataframe$TIME1,"%H:%M:%S"),strptime(dataframe$TIME2,"%H:%M:%S"))

if this helps let us know. thank you

answered Aug 10 '17 at 07:46

Onyambu

1 Answers1