R, intraday data, convert datetime to a different timezone

Question

I have a dataset with intraday data where three important variables are Country, Datetime, Price.

An example could be: Sweden, 2019-12-23 09:08:00, 105.31

This data is downloaded from Bloomberg, and it looks like it uses my local time (Denmark). For example, for Australia I have a market which starts at 23 00 which does not make sense unless it is European time. I would like to convert the time that I have in the data to the local time in that particular country. Of course, I could add or subtract some hours, but the time difference is not fixed: some countries have summer/winter time while other countries don't, and countries which do have summer/winter time may change on different days (for example I think there is about one week between the time change in US and Europe). Do you have an advice how to transform my dataset into the local timezone? So, if it says "2019-12-23 09:08:00", then I would like to know that in that particular country it was 09:08 in the morning (and not in my country). I really hope there is a smart R function for this.

Thanks in advance!

Answer 1

You could use lubridate::force_tz and lubridate::with_tz :

dat <- as.POSIXct("2021-05-01 12:00:00",tz = "UTC")
lubridate::force_tz(dat,tz="CET")
#> [1] "2021-05-01 12:00:00 CEST"
lubridate::with_tz(lubridate::force_tz(dat,tz="UTC"))
#> [1] "2021-05-01 14:00:00 CEST"