Change date format of multiple date columns-CodePudding

I have a large dataframe with multiple date columns. I did like to use str.contains to identify all those date columns and change the format and retain the columns in original dataframe. Here is a sample of the dataset:

dat <- data.frame(
  SSN = c(204,401,101,666,777), 
  date_today=c("1914-01-01","2022-03-12","2021-07-09","1914-01-01","2022-04-05"), 
  date_adm = c("2020-03-11","2022-03-12","NA","2021-04-07","2022-04-05")
 
)

I have tried this code but looks like its very wrong

Data %>% mutate(select(contains("date")), as.Date, format="%d-%m-%Y")

End result is filter columns containing date then change format while retaining those date columns within the origina dataframe.

CodePudding user response：

The code uses select inside, instead, it should be across. In addition, the format should be "%Y-%m-%d"

library(dplyr)
dat %>%
   mutate(across(contains("date"), as.Date, format = "%Y-%m-%d"))

-output

SSN date_today   date_adm
1 204 1914-01-01 2020-03-11
2 401 2022-03-12 2022-03-12
3 101 2021-07-09       <NA>
4 666 1914-01-01 2021-04-07
5 777 2022-04-05 2022-04-05

CodePudding user response：

Use across instead of select. Also you have to pass the right format, i.e. the year comes first in your data (but I wasn't sure about the order of the month and day in your data, so perhaps you have to change that.)

library(dplyr)

dat %>% 
  mutate(across(contains("date"), as.Date, format="%Y-%d-%m"))
#>   SSN date_today   date_adm
#> 1 204 1914-01-01 2020-11-03
#> 2 401 2022-12-03 2022-12-03
#> 3 101 2021-09-07       <NA>
#> 4 666 1914-01-01 2021-07-04
#> 5 777 2022-05-04 2022-05-04