Как конвертировать дату в другом формате
test_date <- c("33440.53", "20190705", "20190329", "20190326", "2019-05-23", "2019/05/14")
b <- test_date
c <- substring(b, first = 1, last = 4)
d <- substring(b, first = 5, last = 6)
e <- substring(b, first = 7, last = 8)
dob <- paste(c,d,e, sep = "/")
вывод
"3344/0./53" "2019/07/05" "2019/03/29" "2019/03/26" "2019/-0/5-" "2019//0/5/"
вывод, который я хочу
"07/21/1991" "07/05/2019" "03/29/2019" "03/26/2019" "05/23/2019" "05/14/2019"