Show UTC offset after parsing datetimes

[damianooldoni]

I like the way readr uses UTC datetimes consistently. I would like to know if there is a way to get the timezone offset specified in a ISO datetime string after reading it with readr. It seems to me that it gets lost. It would be nice to store it somewhere, maybe as an attribute? In example below, the offset I would like to retrieve is "-06:00" which is the ISO way to express offsets.

r <- readr::parse_datetime("2010/01/01 12:00 -0600", "%Y/%m/%d %H:%M %z")
r
#> [1] "2010-01-01 18:00:00 UTC"
attributes(r)
#> $class
#> [1] "POSIXct" "POSIXt" 
#> 
#> $tzone
#> [1] "UTC"
lubridate::tz(r)
#> [1] "UTC"

If the timezone is provided via locale arg, I can retrieve it by using the function tz_offset() from the non tidyverse package lutz, see example below. However, it seems to me more a workaround than a stable, elegant solution:

s <- readr::parse_datetime("2010/01/01 12:00 -0600", "%Y/%m/%d %H:%M %z", 
                    locale = readr::locale(tz = "US/Central"))
s
#> [1] "2010-01-01 12:00:00 CST"
attributes(s)
#> $class
#> [1] "POSIXct" "POSIXt" 
#> 
#> $tzone
#> [1] "US/Central"
lutz::tz_offset(s)
#>      tz_name           date_time zone is_dst utc_offset_h
#> 1 US/Central 2010-01-01 12:00:00  CST  FALSE           -6

Both examples created on 2023-02-01 with reprex v2.0.2

I am interested what you think about this. Thanks in advance.

[hadley]

I think this is unfortunately out of scope for readr since it doesn't have any control over the data structure that R uses for date times.