转换序列日期 [英] Convert serial date

问题描述

我在阅读Excel时遇到问题.带有日期的列正在按顺序读取某些单元格，而另一些则作为日期读取，如下所示.

I am having problems with reading excel. A column with dates is being read some cells in serial and others as date as below.

date<-c("43942", "43945", "43952", "17/05/2020", "17/05/2020",
        "18/05/2020", "19/05/2020", "18/05/2020", "22/05/2020")

如何将下面的向量转换为日期?我将其作为字符串放置，因为这是我要转换的列在阅读后的外观.

How could I convert the vector below to dates? I put it as a string because this is how the column I want to convert looks after reading.

命令

as.Date(date, origin = "1899-12-30")

返回错误和

as.Date(as.numeric(date), origin = "1899-12-30")

在NA中转换非序列日期.

convert in NA the non-serial dates.

推荐答案

您可以按任意顺序分两个步骤进行处理.

You can handle this in two steps in any order.

将数字转换为日期

new_date <- as.Date(as.numeric(date), origin = "1899-12-30")

这将为无法转换为数字的日期返回警告.

This will return warnings for dates that cannot be converted to numeric.

使用"dmy" 格式

new_date[is.na(new_date)] <- as.Date(date[is.na(new_date)], "%d/%m/%Y")
#Or using lubridate's dmy
#new_date[is.na(new_date)] <- lubridate::dmy(date[is.na(new_date)])

new_date
#[1] "2020-04-21" "2020-04-24" "2020-05-01" "2020-05-17" "2020-05-17" "2020-05-18"
#[7] "2020-05-19" "2020-05-18" "2020-05-22"

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