r - Extract time from timestamp?

Question

Essentially, I want only the hour, minute, and seconds from a column of timestamps I have in R, because I want to view how often different data points occur throughout different times of day and day and date is irrelevant.

However, this is how the timestamps are structured in the dataset: 2008-08-07T17:07:36Z

And I'm unsure how to only get that time from this timestamp.

Thank you for any help you can provide and please just let me know if I can provide more information!

Answer 1

We can use strptime to convert to a datetime class and then format to extract the hour:min:sec.

dtime <- strptime(str1, "%Y-%m-%dT%H:%M:%SZ")
format(dtime, "%H:%M:%S")
#[1] "17:07:36"

If the OP wants to have the hour, min, sec as separate columns

read.table(text=format(dtime, "%H:%M:%S"), sep=":", header=FALSE)
#  V1 V2 V3
#1 17  7 36

---

Another option is using lubridate

library(lubridate)
format(ymd_hms(str1), "%H:%M:%S")
#[1] "17:07:36"

data

str1 <- "2008-08-07T17:07:36Z"