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force_tz() should convert dates to date-times #675
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I think the last two should return POSIX instead of date. I would qualify this as a bug. Do you also find the first example unexpected? This is a new addition in the last minor version to avoid dealing explicitly with the NULL tzs, but I am not entirely convinced it was such a good idea. |
I strongly recommend against up-converting dates to datetime in general, and I think doing so implicitly would be asking for trouble. The typical approach there is to assume the time is all-zeroes, but then I hadn't thought of it when I created this issue, but on reflection, yes I think the first result is unexpected, given that I have a non-UTC locale set. Would it make sense to drop timezones from time-free Potential problems might include edge cases like Samoa's missing day (https://zachholman.com/talk/utc-is-enough-for-everyone-right). |
You ask for an operation which makes sense on date-times, that implise that you are interpreting the date as an instant. Otherwise why would you do force_tz on a date?
Yes. I will revert it to NULL. |
I agree I'm happy to help with code, though I won't have time until at least tomorrow. Sounds like you want |
It seems reasonable to me to return POSIXct when you explicit request a timezone be added to a Date. Adding a tzone attribute to a Date object is definitely wrong: library(lubridate, warn.conflicts = FALSE)
tz(force_tz(today(), "America/New_York"))
#> [1] "UTC"
class(force_tz(today(), "America/New_York"))
#> [1] "Date"
tz(with_tz(today(), "America/New_York"))
#> [1] "America/New_York"
class(with_tz(today(), "America/New_York"))
#> [1] "Date"
tz(`tz<-`(today(), "America/New_York"))
#> [1] "UTC"
class(`tz<-`(today(), "America/New_York"))
#> [1] "Date" Created on 2019-11-20 by the reprex package (v0.3.0) (I agree that lubridate seems to upclass dates to date-times too readily; but that's a separate issue) |
Version 1.7.10 ============== ### NEW FEATURES * `fast_strptime()` and `parse_date_time2()` now accept multiple formats and apply them in turn ### BUG FIXES * [#926](tidyverse/lubridate#926) Fix incorrect division of intervals by months involving leap years * Fix incorrect skipping of digits during parsing of the `%z` format Version 1.7.9.2 =============== ### NEW FEATURES * [#914](tidyverse/lubridate#914) New `rollforward()` function * [#928](tidyverse/lubridate#928) On startup lubridate now resets TZDIR to a proper directory when it is set to non-dir values like "internal" or "macOS" (a change introduced in R4.0.2) * [#630](tidyverse/lubridate#630) New parsing functions `ym()` and `my()` ### BUG FIXES * [#930](tidyverse/lubridate#930) `as.period()` on intervals now returns valid Periods with double fields (not integers) Version 1.7.9 ============= ### NEW FEATURES * [#871](tidyverse/lubridate#893) Add `vctrs` support ### BUG FIXES * [#890](tidyverse/lubridate#890) Correctly compute year in `quarter(..., with_year = TRUE)` * [#893](tidyverse/lubridate#893) Fix incorrect parsing of abbreviated months in locales with trailing dot (regression in v1.7.8) * [#886](tidyverse/lubridate#886) Fix `with_tz()` for POSIXlt objects * [#887](tidyverse/lubridate#887) Error on invalid numeric input to `month()` * [#889](tidyverse/lubridate#889) Export new dmonth function Version 1.7.8 ============= ### NEW FEATURES * (breaking) Year and month durations now assume 365.25 days in a year consistently in conversion and constructors. Particularly `dyears(1) == years(1)` is now `TRUE`. * Format and print methods for 0-length objects are more consistent. * New duration constructor `dmonths()` to complement other duration constructors. * * `duration()` constructor now accepts `months` and `years` arguments. * [#629](tidyverse/lubridate#629) Added `format_ISO8601()` methods. * [#672](tidyverse/lubridate#672) Eliminate all partial argument matches * [#674](tidyverse/lubridate#674) `as_date()` now ignores the `tz` argument * [#675](tidyverse/lubridate#675) `force_tz()`, `with_tz()`, `tz<-` convert dates to date-times * [#681](tidyverse/lubridate#681) New constants `NA_Date_` and `NA_POSIXct_` which parallel built-in primitive constants. * [#681](tidyverse/lubridate#681) New constructors `Date()` and `POSIXct()` which parallel built-in primitive constructors. * [#695](tidyverse/lubridate#695) Durations can now be compared with numeric vectors. * [#707](tidyverse/lubridate#707) Constructors return 0-length inputs when called with no arguments * [#713](tidyverse/lubridate#713) (breaking) `as_datetime()` always returns a `POSIXct()` * [#717](tidyverse/lubridate#717) Common generics are now defined in `generics` dependency package. * [#719](tidyverse/lubridate#719) Negative Durations are now displayed with leading `-`. * [#829](tidyverse/lubridate#829) `%within%` throws more meaningful messages when applied on unsupported classes * [#831](tidyverse/lubridate#831) Changing hour, minute or second of Date object now yields POSIXct. * [#869](tidyverse/lubridate#869) Propagate NAs to all internal components of a Period object ### BUG FIXES * [#682](tidyverse/lubridate#682) Fix quarter extraction with small `fiscal_start`s. * [#703](tidyverse/lubridate#703) `leap_year()` works with objects supported by `year()`. * [#778](tidyverse/lubridate#778) `duration()/period()/make_difftime()` work with repeated units * `c.Period` concatenation doesn't fail with empty components. * Honor `exact = TRUE` argument in `parse_date_time2`, which was so far ignored. Version 1.7.4 ============= ### NEW FEATURES * [#658](tidyverse/lubridate#658) `%within%` now accepts a list of intervals, in which case an instant is checked if it occurs within any of the supplied intervals. ### CHANGES * [#661](tidyverse/lubridate#661) Throw error on invalid multi-unit rounding. * [#633](tidyverse/lubridate#633) `%%` on intervals relies on `%m+` arithmetic and doesn't produce NAs when intermediate computations result in non-existent dates. * `tz()` always returns "UTC" when `tzone` attribute cannot be inferred. ### BUG FIXES * [#664](tidyverse/lubridate#664) Fix lookup of period functions in `as.period` * [#649](tidyverse/lubridate#664) Fix system timezone memoization Version 1.7.3 ============= ### BUG FIXES * [#643](tidyverse/lubridate#643), [#640](tidyverse/lubridate#640), [#645](tidyverse/lubridate#645) Fix faulty caching of system timezone.
Perhaps this is intentional, but it strikes me as unexpected:
Latest Github version, 1.7.4.
In general, timezones for pure
Date
s seem to be discouraged in that virtually no lubridate functions will ever return a non-UTC date (e.g.today
,as_date
,date
, etc.), but I can't find anything to this effect in the docs.The text was updated successfully, but these errors were encountered: