将字符格式的日期+时间转换为 CET，同时正确考虑夏令时

Question

我在转换一些字符时遇到一个小问题（格式是CET，它们只是存储为字符）。我想将格式从字符更改为日期，以便我可以在时区之间进行转换。这是我正在查看的一小部分数据。

timestamps <- c("2023-10-29 00:00:00", "2023-10-29 00:15:00", "2023-10-29 00:30:00", "2023-10-29 00:45:00", "2023-10-29 01:00:00", "2023-10-29 01:15:00", "2023-10-29 01:30:00", "2023-10-29 01:45:00", "2023-10-29 02:00:00", "2023-10-29 02:15:00", "2023-10-29 02:30:00", "2023-10-29 02:45:00", "2023-10-29 03:00:00", "2023-10-29 02:15:00", "2023-10-29 02:30:00", "2023-10-29 02:45:00", "2023-10-29 03:00:00", "2023-10-29 03:15:00", "2023-10-29 03:30:00", "2023-10-29 03:45:00", "2023-10-29 04:00:00", "2023-10-29 04:15:00")

我的第一次尝试是执行以下操作：

as.POSIXct(timestamps, tz = "CET")

但这给出了以下输出：

 [1] "2023-10-29 00:00:00 CEST" "2023-10-29 00:15:00 CEST" "2023-10-29 00:30:00 CEST" "2023-10-29 00:45:00 CEST" "2023-10-29 01:00:00 CEST"
 [6] "2023-10-29 01:15:00 CEST" "2023-10-29 01:30:00 CEST" "2023-10-29 01:45:00 CEST" "2023-10-29 02:00:00 CEST" "2023-10-29 02:15:00 CET" 
[11] "2023-10-29 02:30:00 CET"  "2023-10-29 02:45:00 CET"  "2023-10-29 03:00:00 CET"  "2023-10-29 02:15:00 CET"  "2023-10-29 02:30:00 CET" 
[16] "2023-10-29 02:45:00 CET"  "2023-10-29 03:00:00 CET"  "2023-10-29 03:15:00 CET"  "2023-10-29 03:30:00 CET"  "2023-10-29 03:45:00 CET" 
[21] "2023-10-29 04:00:00 CET"  "2023-10-29 04:15:00 CET" 

此处 CEST 时区未正确分配。它们应该分配到“2023-10-29 03:00:00”时间戳。

我还尝试使用 lubridate 中的“ymd_hms”，但这也没有成功：

[1] "2023-10-29 00:00:00 CEST" "2023-10-29 00:15:00 CEST" "2023-10-29 00:30:00 CEST" "2023-10-29 00:45:00 CEST" "2023-10-29 01:00:00 CEST"
 [6] "2023-10-29 01:15:00 CEST" "2023-10-29 01:30:00 CEST" "2023-10-29 01:45:00 CEST" "2023-10-29 02:00:00 CET"  "2023-10-29 02:15:00 CET" 
[11] "2023-10-29 02:30:00 CET"  "2023-10-29 02:45:00 CET"  "2023-10-29 03:00:00 CET"  "2023-10-29 02:15:00 CET"  "2023-10-29 02:30:00 CET" 
[16] "2023-10-29 02:45:00 CET"  "2023-10-29 03:00:00 CET"  "2023-10-29 03:15:00 CET"  "2023-10-29 03:30:00 CET"  "2023-10-29 03:45:00 CET" 
[21] "2023-10-29 04:00:00 CET"  "2023-10-29 04:15:00 CET" 

实际上，与以前相比，现在分配给“CEST”时区的时间段减少了 1 个时间段。 有没有人有办法解决这个问题？

Answer 1

如果您假设数据已排序，则可以为 (

+0100

)

duplicated

次添加

CET

，为

+0200

次添加

CEST

，然后在

%z

调用中添加

as.POSIXct

。

ifelse(duplicated(timestamps) | as.POSIXct(timestamps, tz = "CET") > as.POSIXct("2023-10-29 03:00:00"),
       paste0(timestamps, " +0100"),
       paste0(timestamps, " +0200")
       ) |> 
  as.POSIXct(format="%Y-%m-%d %H:%M:%S %z")

给予：

[1] "2023-10-29 00:00:00 CEST" "2023-10-29 00:15:00 CEST" "2023-10-29 00:30:00 CEST" "2023-10-29 00:45:00 CEST" "2023-10-29 01:00:00 CEST" "2023-10-29 01:15:00 CEST"
 [7] "2023-10-29 01:30:00 CEST" "2023-10-29 01:45:00 CEST" "2023-10-29 02:00:00 CEST" "2023-10-29 02:15:00 CEST" "2023-10-29 02:30:00 CEST" "2023-10-29 02:45:00 CEST"
[13] "2023-10-29 02:00:00 CET"  "2023-10-29 02:15:00 CET"  "2023-10-29 02:30:00 CET"  "2023-10-29 02:45:00 CET"  "2023-10-29 03:00:00 CET"  "2023-10-29 03:15:00 CET" 
[19] "2023-10-29 03:30:00 CET"  "2023-10-29 03:45:00 CET"  "2023-10-29 04:00:00 CET"  "2023-10-29 04:15:00 CET"