POSIXct日期转换错误 [英] POSIXct date conversion error

问题描述

将字符格式的一组日期转换为POSIXct对象时，遇到以下错误。

I've encountered the following error when converting a set of dates in character format to a POSIXct object.

示例数据：

t<-c("3/11/2007 1:30", "3/11/2007 2:00", "4/11/2007 2:00")

str(t)

chr [1:3] "3/11/2007 1:30" "3/11/2007 2:00" "4/11/2007 2:00"

z<-as.POSIXct(strptime(t, format ="%m/%d/%Y  %H:%M"))

z
"2007-03-11 01:30:00 MST" NA                        "2007-04-11 02:00:00 MDT"

str(z)

POSIXct[1:3], format: "2007-03-11 01:30:00" NA "2007-04-11 02:00:00"

我的问题是为什么是z中第二个日期返回的NA吗？我有一个数据集包含8年的小时数据（从中我复制了上面的日期），这个NA错误仅在3/8 - 3/14之间的时间弹出，而当时间是02:00:00时才会弹出。

My question is why is the NA returned for the second date in z? I have a dataset that contains 8 years of hourly data (from which I copied the dates above), and this NA error pops up only for dates between 3/8 - 3/14 and ONLY when the hour is 02:00:00.

如果日期转换为POSIXlt，我不会遇到错误，所以这是我目前的工作。

I do not encounter an error if the dates are converted to POSIXlt, so that is my current work around.

任何想法？

推荐答案

尝试使用一个时区不使用夏令时：

Try using a time zone that does not use daylight savings time:

as.POSIXct(t, format = "%m/%d/%Y  %H:%M", tz = "GMT")
## [1] "2007-03-11 01:30:00 GMT" "2007-03-11 02:00:00 GMT" "2007-04-11 02:00:00 GMT"

这篇关于POSIXct日期转换错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！