[Fix #1085] Preserve time zone of the input POSIXt in as_datetime

tidyverse · Nov 5, 2022 · fbd991d · fbd991d
1 parent c4cb901
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Showing 5 changed files with 16 additions and 6 deletions.
diff --git a/NEWS.md b/NEWS.md
@@ -20,6 +20,7 @@ Version 1.8.0.9000
 
 ### BUG FIXES
 
+* [#1085](https://github.com/tidyverse/lubridate/issues/1085) `as_datetime()` now preserves the time zone of the POSIXt input.
 * [#1072](https://github.com/tidyverse/lubridate/issues/1072) Names are now handled correctly when combining multiple Period or Interval objects.
 * [#1003](https://github.com/tidyverse/lubridate/issues/1003) Correctly handle r and R formats in locales which have no p format
 * [#1074](https://github.com/tidyverse/lubridate/issues/1074) Fix concatination of named Period, Interval and Duration vectors.

diff --git a/R/accessors-tz.r b/R/accessors-tz.r
@@ -74,12 +74,10 @@ tz.logical <- function(x) {
 
 #' @export
 tz.default <- function(x) {
-  ### FIXME: make this `stop` in next major release
-  ## VS[21-03-2020]: v.1.7.8 already sent notification to broken packages
   warning(
     "tz(): Don't know how to compute timezone for object of class ",
     paste0(class(x), collapse = "/"),
-    "; returning \"UTC\". This warning will become an error in the next major version of lubridate.",
+    "; returning \"UTC\".",
     call. = FALSE
   )
   "UTC"

diff --git a/R/coercion.r b/R/coercion.r
@@ -772,15 +772,15 @@ setGeneric("as_datetime",
 #' @rdname as_date
 #' @export
 setMethod("as_datetime", "ANY",
-  function(x, tz = "UTC") {
+  function(x, tz = lubridate::tz(x)) {
     with_tz(as.POSIXct(x, tz = tz), tzone = tz)
   }
 )
 
 #' @rdname as_date
 #' @export
 setMethod("as_datetime", "POSIXt",
-  function(x, tz = "UTC") {
+  function(x, tz = lubridate::tz(x)) {
     with_tz(x, tz)
   }
 )

diff --git a/tests/testthat/test-POSIXt.R b/tests/testthat/test-POSIXt.R
@@ -95,7 +95,7 @@ test_that("converts character", {
 })
 
 test_that("changes timezone of POSIXct", {
-  dt <- as_datetime(make_datetime(tz = "America/Chicago"))
+  dt <- as_datetime(make_datetime(tz = "America/Chicago"), tz = "UTC")
   expect_equal(tz(dt), "UTC")
 })
 

diff --git a/tests/testthat/test-time-zones.R b/tests/testthat/test-time-zones.R
@@ -255,3 +255,14 @@ test_that("If original post/pre is known, ignore roll_DST", {
       tzone_out = "America/Chicago",
       roll_dst = "post"))
 })
+
+
+test_that("as_datetime does not loose time zone", {
+  ## #1085
+  x <- ymd_hms("2022-01-01 23:40:36", tz = "US/Pacific")
+  expect_identical(x, as_datetime(x))
+  expect_identical(with_tz(x, "Europe/Amsterdam"), as_datetime(x, tz = "Europe/Amsterdam"))
+  x <- as.POSIXlt(x)
+  expect_identical(x, as_datetime(x))
+  expect_identical(with_tz(x, "Europe/Amsterdam"), as_datetime(x, tz = "Europe/Amsterdam"))
+})