[jira] [Updated] (ARROW-14200) [R] [C++] strftime on a date should not use or be confused by timezones

["Jonathan Keane (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARROW-14200?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jonathan Keane updated ARROW-14200:
-----------------------------------
    Issue Type: Bug  (was: New Feature)

> [R] [C++] strftime on a date should not use or be confused by timezones
> -----------------------------------------------------------------------
>
>                 Key: ARROW-14200
>                 URL: https://issues.apache.org/jira/browse/ARROW-14200
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: C++, R
>            Reporter: Jonathan Keane
>            Priority: Major
>
> When the input to {{strftime}} is a date, timezones shouldn't be necessary or assumed.
> What I think is going on below is the date 1992-01-01 is being interpreted as 1992-01-01 00:00:00 in UTC, and then when {{strftime()}} is being called it's displaying that timestamp as 1991-12-31 ... (since my system is set to an after UTC timezone), and then taking the year out of it. If I specify {{tz = "utc"}} in the {{strftime()}}, I get the expected result (though that shouldn't be necessary).
> Run in the US central timezone:
> {code}
> library(arrow, warn.conflicts = FALSE)
> library(dplyr, warn.conflicts = FALSE)
> library(lubridate, warn.conflicts = FALSE)
> Table$create(
>   data.frame(
>     x = as.Date("1992-01-01")
>   )
> ) %>% 
>   mutate(
>     as_int_strftime = as.integer(strftime(x, "%Y")),
>     strftime = strftime(x, "%Y"),
>     as_int_strftime_utc = as.integer(strftime(x, "%Y", tz = "UTC")),
>     strftime_utc = strftime(x, "%Y", tz = "UTC"),
>     year = year(x)
>   ) %>%
>   collect()
> #>            x as_int_strftime strftime as_int_strftime_utc strftime_utc year
> #> 1 1992-01-01            1991     1991                1992         1992 1992
> {code}



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