Should time zones be changing datetime formatting?

It seems like (not) specifying a time zone makes datetime columns print differently?

library(tibble)
chr_date <- "05/04/23 19:22:21"

tibble(a = as.POSIXct(chr_date, "%d/%m/%y %H:%M:%S", tz = "UTC"),
       b = as.POSIXct(chr_date, "%d/%m/%y %H:%M:%S"))
#> # A tibble: 1 × 2
#>   a                   b               
#>   <dttm>              <dttm>          
#> 1 2023-04-05 19:22:21 5-04-23 19:22:21

^{Created on 2023-04-05 by the reprex package (v2.0.1)}

Session info

``` r sessioninfo::session_info() #> ─ Session info ─────────────────────────────────────────────────────────────── #> setting value #> version R version 4.0.5 (2021-03-31) #> os Red Hat Enterprise Linux #> system x86_64, linux-gnu #> ui X11 #> language (EN) #> collate en_GB.UTF-8 #> ctype en_GB.UTF-8 #> tz Europe/London #> date 2023-04-05 #> pandoc 2.14.0.3 @ /usr/lib/rstudio-server/bin/pandoc/ (via rmarkdown) #> #> ─ Packages ─────────────────────────────────────────────────────────────────── #> package * version date (UTC) lib source #> cli 3.6.0 2023-01-09 [1] CRAN (R 4.0.5) #> digest 0.6.31 2022-12-11 [1] CRAN (R 4.0.5) #> evaluate 0.20 2023-01-17 [1] CRAN (R 4.0.5) #> fansi 1.0.3 2022-03-24 [1] CRAN (R 4.0.5) #> fastmap 1.1.0 2021-01-25 [1] CRAN (R 4.0.5) #> fs 1.6.1 2023-02-06 [1] CRAN (R 4.0.5) #> glue 1.6.2 2022-02-24 [1] CRAN (R 4.0.5) #> htmltools 0.5.4 2022-12-07 [1] CRAN (R 4.0.5) #> knitr 1.42 2023-01-25 [1] CRAN (R 4.0.5) #> lifecycle 1.0.3 2022-10-07 [1] CRAN (R 4.0.5) #> magrittr 2.0.3 2022-03-30 [1] CRAN (R 4.0.5) #> pillar 1.8.1 2022-08-19 [1] CRAN (R 4.0.5) #> pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.0.5) #> purrr 0.3.4 2020-04-17 [1] CRAN (R 4.0.5) #> R.cache 0.16.0 2022-07-21 [1] CRAN (R 4.0.5) #> R.methodsS3 1.8.2 2022-06-13 [1] CRAN (R 4.0.5) #> R.oo 1.25.0 2022-06-12 [1] CRAN (R 4.0.5) #> R.utils 2.12.1 2022-10-30 [1] CRAN (R 4.0.5) #> reprex 2.0.1 2021-08-05 [2] CRAN (R 4.0.5) #> rlang 1.0.6 2022-09-24 [1] CRAN (R 4.0.5) #> rmarkdown 2.20 2023-01-19 [1] CRAN (R 4.0.5) #> rstudioapi 0.13 2020-11-12 [2] CRAN (R 4.0.5) #> sessioninfo 1.2.2 2021-12-06 [2] CRAN (R 4.0.5) #> styler 1.8.1 2022-11-07 [1] CRAN (R 4.0.5) #> tibble * 3.1.8 2022-07-22 [1] CRAN (R 4.0.5) #> utf8 1.2.2 2021-07-24 [1] CRAN (R 4.0.5) #> vctrs 0.5.0 2022-10-22 [1] CRAN (R 4.0.5) #> withr 2.5.0 2022-03-03 [1] CRAN (R 4.0.5) #> xfun 0.37 2023-01-31 [1] CRAN (R 4.0.5) #> yaml 2.3.7 2023-01-23 [1] CRAN (R 4.0.5) #> #> [1] /home/333573/R/x86_64-pc-linux-gnu-library/4.0 #> [2] /opt/R/4.0.5/lib/R/library #> #> ────────────────────────────────────────────────────────────────────────────── ```

r-lib / pillar

Should time zones be changing datetime formatting? #643