在R中使用as.Date转换为日期并获得“NA”系列

Question

Using the following code to try to get my date column into the right format, but it's just returning all of the dates as "NA".

setwd("C:\\Users\\user\\Documents\\Files\\a")
data <- read.csv("file1.csv")

data$Date <- as.Date(data$Date, format = "d%/m%/Y%")

Edit: date values as follows: 11/09/2009

Answer 1

来自?as.Date文档：

If the date string does not specify the date completely, the returned answer may be system-specific. The most common behaviour is to assume that a missing year, month or day is the current one. If it specifies a date incorrectly, reliable implementations will give an error and the date is reported as 'NA'. Unfortunately some common implementations (such as 'glibc') are unreliable and guess at the intended meaning.

data$Date <- as.Date(data$Date, format = "%d/%m/%Y")

Answer 2

You could try converting the date with the package lubridate

library(lubridate)
date <- parse_date_time(x = date,
                orders = c("d m y", "d B Y", "mdy"),
                locale = "eng")

After you may specify which format you want the date to be:

character_date <- as.character(as.Date(date, "%m/%d/%Y"), format = "%m/%d/%Y")