This is the input
library(lubridate)
        library(tidyverse)
        library(stringr)
        library(dplyr) 
        dataset <- data.frame(A = c("12345 Software Inc","12346 Software In","123463 Software In"),
                      B = c(12345,1234523,234234234),
                      C = c(ABC-1244, DEF-1134,ACF-1234),
                      X.Y DATE = c("1-May-2019","2-Jun-2020","3-July-2020"),
                      XX.YY DATE = c("1-May-2019","5-Jun-2020","4-July-2020"),
                      Check_DATE = c("1-May-2019","2-Jun-2020","3-July-2020")
)
        date_parser <- function(column){
              if(any(grepl("[-]",column))){
                format(parse_date_time(column,orders = c("bdy","dmy","dby","ymd","mdy","ydm","%d-%m-%Y %H:%M:%S","%m-%d-%Y %H:%M:%S","%Y-%m-%d %H:%M:%S","%d-%m-%Y","%d-%b-%Y")),"%d-%m-%Y")
              }
              else column
            }
            date_format_change <- function(dataset1) { 
              data <- dataset1 %>% 
                mutate_at(-1,~ stringr::str_replace_all(.,"\\/","-")) %>% 
                purrr::map_dfr(~date_parser(.))
              View(data)
            }
            date_format_change(dataset)
Output Received : [![enter image description here][2]][2]
  [1]: https://i.stack
.
The Date has not changed. and  there columns have become NA. I want the output should not have any NA columns and date should be DD-MM-YYYY
there columns have become NA. I want the output should not have any NA columns and date should be DD-MM-YYYY
 
    