[R-pkg-devel] Issue handling datetimes: possible differences between computers

[Jeff Newmiller]

I have no idea how to get readxl::read_excel to import a timestamp column in a timezone. It is true that Excel has no concept of timezones, but the data one finds there usually came from a text file at some point. Importing as character is a feasible strategy, but trying to convince an intermediate user to go to that much trouble is a headache when the issue is ignored in the help file.

It is evidently possible to specify a locale input to readr::read_csv, but the default behaviour guesses timestamp columns and assumes "UTC", and a file may contain data from different timezones (UTC and local civil are a common combination). Again, character import and manual conversion are needed.

On October 10, 2022 9:40:42 AM PDT, Hadley Wickham <h.wickham using gmail.com> wrote:
>On Sun, Oct 9, 2022 at 9:31 PM Jeff Newmiller <jdnewmil using dcn.davis.ca.us> wrote:
>>
>> ... which is why tidyverse functions and Python datetime handling irk me so much.
>>
>> Is tidyverse time handling intrinsically broken? They have a standard practice of reading time as UTC and then using force_tz to fix the "mistake". Same as Python.
>
>Can you point to any docs that lead you to this conclusion so we can
>get them fixed? I strongly encourage people to parse date-times in the
>correct time zone; this is why lubridate::ymd_hms() and friends have a
>tz argument.
>
>Hadley
>

-- 
Sent from my phone. Please excuse my brevity.