Should use_tz adjust the input time?

[gadenbuie]

Prework

• Read and agree to the code of conduct and contributing guidelines.
• If there is already a relevant issue, whether open or closed, comment on the existing thread instead of posting a new issue.
• Post a minimal reproducible example so the maintainer can troubleshoot the problems you identify. A reproducible example is:
  • Runnable: post enough R code and data so any onlooker can create the error on their own computer.
  • Minimal: reduce runtime wherever possible and remove complicated details that are irrelevant to the issue at hand.
  • Readable: format your code according to the tidyverse style guide.

Description

I was expecting that use_tz would translate the input time into the timezone provided to use_tz, but it seems to not be having an effect.

Reproducible example

dt <- withr::with_timezone("UTC", Sys.time())
attr(dt, "tzone") <- "UTC"

strftime(dt, "%F %T", tz = "UTC")
#> [1] "2023-03-22 13:55:52"
strftime(dt, "%F %T", tz = "America/New_York")
#> [1] "2023-03-22 09:55:52"

bigD::fdt(dt)
#> [1] "2023-03-22T13:55:52Z"
bigD::fdt(dt, use_tz = "America/New_York")
#> [1] "2023-03-22T13:55:52Z"

Expected result

I was expecting the output of fdt() to use the America/New_York timezone without me having to adjust the input time object.

attr(dt, "tzone") <- "America/New_York"
bigD::fdt(dt)
#> [1] "2023-03-22T09:55:52-04:00"

Session info

Session info

sessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value
#>  version  R version 4.2.2 (2022-10-31)
#>  os       macOS Big Sur ... 10.16
#>  system   x86_64, darwin17.0
#>  ui       X11
#>  language (EN)
#>  collate  en_US.UTF-8
#>  ctype    en_US.UTF-8
#>  tz       America/New_York
#>  date     2023-03-22
#>  pandoc   2.19.2 @ /Applications/RStudio.app/Contents/Resources/app/quarto/bin/tools/ (via rmarkdown)
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version    date (UTC) lib source
#>  bigD          0.2.0.9000 2023-03-22 [1] Github (rstudio/bigd@8fba5c6)
#>  cli           3.6.0      2023-01-09 [1] CRAN (R 4.2.0)
#>  digest        0.6.31     2022-12-11 [1] CRAN (R 4.2.0)
#>  evaluate      0.19       2022-12-13 [1] CRAN (R 4.2.0)
#>  fansi         1.0.3      2022-03-24 [1] CRAN (R 4.2.0)
#>  fastmap       1.1.0      2021-01-25 [1] CRAN (R 4.2.0)
#>  fs            1.5.2      2021-12-08 [1] CRAN (R 4.2.0)
#>  glue          1.6.2      2022-02-24 [1] CRAN (R 4.2.0)
#>  htmltools     0.5.4      2022-12-07 [1] CRAN (R 4.2.0)
#>  knitr         1.42       2023-01-25 [1] CRAN (R 4.2.0)
#>  lifecycle     1.0.3      2022-10-07 [1] CRAN (R 4.2.0)
#>  magrittr      2.0.3      2022-03-30 [1] CRAN (R 4.2.0)
#>  pillar        1.8.1      2022-08-19 [1] CRAN (R 4.2.1)
#>  pkgconfig     2.0.3      2019-09-22 [1] CRAN (R 4.2.0)
#>  purrr         1.0.1      2023-01-10 [1] CRAN (R 4.2.0)
#>  R.cache       0.15.0     2021-04-30 [1] CRAN (R 4.2.0)
#>  R.methodsS3   1.8.1      2020-08-26 [1] CRAN (R 4.2.0)
#>  R.oo          1.24.0     2020-08-26 [1] CRAN (R 4.2.0)
#>  R.utils       2.11.0     2021-09-26 [1] CRAN (R 4.2.0)
#>  reprex        2.0.2      2022-08-17 [1] CRAN (R 4.2.0)
#>  rlang         1.0.6      2022-09-24 [1] CRAN (R 4.2.0)
#>  rmarkdown     2.20       2023-01-19 [1] CRAN (R 4.2.0)
#>  rstudioapi    0.14       2022-08-22 [1] CRAN (R 4.2.0)
#>  sessioninfo   1.2.2      2021-12-06 [1] CRAN (R 4.2.0)
#>  styler        1.7.0      2022-03-13 [1] CRAN (R 4.2.0)
#>  tibble        3.1.8      2022-07-22 [1] CRAN (R 4.2.0)
#>  utf8          1.2.2      2021-07-24 [1] CRAN (R 4.2.0)
#>  vctrs         0.5.1      2022-11-16 [1] CRAN (R 4.2.0)
#>  withr         2.5.0      2022-03-03 [1] CRAN (R 4.2.0)
#>  xfun          0.36       2022-12-21 [1] CRAN (R 4.2.0)
#>  yaml          2.3.6      2022-10-18 [1] CRAN (R 4.2.0)
#> 
#>  [1] /Users/garrick/Library/R/x86_64/4.2/library
#>  [2] /Library/Frameworks/R.framework/Versions/4.2/Resources/library
#> 
#> ──────────────────────────────────────────────────────────────────────────────