How to get date type format?

Question

I have a date in yyyymmdd format dataframe

ex.

df= data.frame(dat = seq.Date(from= as.Date("2021-01-01") , to = as.Date("2021-01-07"), by =1))

I want to create a column of strings in this format:

example : 2021-01-07 should look like 07-JAN-21

Answer 1

toupper(format(date_column, "%d-%b-%y"))

here is the premise

> df$dat <- toupper(format(df$dat, "%d-%b-%y"))
> df
        dat
1 01-JAN-21
2 01-FEB-21
3 01-MAR-21
4 01-APR-21
5 01-MAY-21
6 01-JUN-21
7 01-JUL-21