Better representation of datetime differences

Question

How do I convert my results (time differences) in the following three format (preferably using lubridate)

1. HH:MM
2. HH:MM:SS
3. MM:SS

library(lubridate)

time_1 <- ymd_hms("2021-01-01 12:00:00")
time_2 <- ymd_hms("2021-01-01 12:12:36")
time_3 <- ymd_hms("2021-01-01 14:25:45")

time_diff_32 <- time_3 - time_2
time_diff_31 <- time_3 - time_1
time_diff_21 <- time_2 - time_1

Answer 1

Instead of directly doing the -, use difftime with units which will have more control on the output units i.e. if we convert it to seconds, then we can use the seconds_to_period from lubridate and then extract the various components to create the format as in expected output

library(lubridate)
out <- seconds_to_period(difftime(time_3, time_2, units = 'sec'))
sprintf('%02d:%02d', out@hour, second(out))
sprintf('%02d:%02d:%02d', out@hour, out@minute, second(out))
sprintf('%02d:%02d',  out@minute, second(out))

---

If there are more than one object, we can create a function for reuse

f1 <- function(time1, time2, format = "HH:MM") {
   tmp <- lubridate::seconds_to_period(difftime(time2, time1, units = 'sec'))
   switch(format, 
         "HH:MM" = sprintf('%02d:%02d', tmp@hour, second(tmp)),
          "HH:MM:SS" = sprintf('%02d:%02d:%02d', tmp@hour, 
               tmp@minute,  second(tmp)),
          "MM:SS" = sprintf('%02d:%02d',  tmp@minute,
         second(tmp)))
}

-testing

> f1(time_2, time_3)
[1] "02:09"
> f1(time_2, time_3, format = "HH:MM:SS")
[1] "02:13:09"
> f1(time_2, time_3, format = "MM:SS")
[1] "13:09"