如何将字符和日期转换为日期?

How to convert character and dates to dates?

我的数据来自excel。日期采用 dd/mm/yyyy 格式:

certificado$fecha <- c("22/02/2019", "43679", "22/02/2019", "22/01/2019", "28/10/2019", 
"18/09/2019")

但是,R 正在将一些日期读取为 mm/dd/yyyy。我的代码应该将它们全部转换为特定格式。

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

但由于日期格式问题,我收到了 NA。

如果您无法从源头解决此问题,此代码会找到两种格式:

vec <- c("22/02/2019", "43679", "22/02/2019", "22/01/2019", "28/10/2019", "18/09/2019")
out <- as.Date(vec, format = "%d/%m/%Y")
out
# [1] "2019-02-22" NA           "2019-02-22" "2019-01-22" "2019-10-28" "2019-09-18"

isna <- is.na(out)
out[isna] <- as.Date(as.integer(vec[isna]), origin = "1900-01-01")
out
# [1] "2019-02-22" "2019-08-04" "2019-02-22" "2019-01-22" "2019-10-28" "2019-09-18"