Date formatted cell in xlsx files to R

问题

I have an excel file which has date information in some cells. like :

I read this file into R by the following command :

library(xlsx)

data.files = list.files(pattern = "*.xlsx")
data <- lapply(data.files, function(x) read.xlsx(x, sheetIndex = 9,header = T))

Everything is correct except the cells with date! instead of having the xlsx information into those cell, I always have 42948 as a date :

Does anybody know how could I fix this ?

回答1:

As you can see, after importing your files, dates are represented as numeric values (here 42948). They are actually the internal representation of the date information in Excel. Those values are the ones that R presents instead of the “real” dates.

You can get those dates in R with as.Date(42948 - 25569, origin = "1970-01-01")

Notice that you can also use a vector containing the internal representation of the dates, so this should also work

vect <- c(42948, 42949, 42950)
as.Date(vect - 25569, origin = "1970-01-01")

PS: To convert an Excel datetime colum, see this (p.31)

来源：https://stackoverflow.com/questions/46469727/date-formatted-cell-in-xlsx-files-to-r