Convert character to date and numeric, maintain same format - r

Question

In the output of the code below the variables day and sales are in the format that I need but not the type, it outputs type chr instead. The variables should be date and num respectively. I've tried many things but either I get chr or some sort of error. For instance, using as.Date() doesn´t change the variable day to the format "%d/%m/%Y". The code with sample data:
library(dplyr)
library(lubridate)
df <- data.frame(matrix(c("2017-09-04","2017-09-05",103,104,17356,18022),ncol = 3, nrow = 2))
colnames(df) <- c("DATE","ORDER_ID","SALES")
df$DATE <- as.Date(df$DATE, format = "%Y-%m-%d")
df$SALES <- as.numeric(as.character(df$SALES))
df$ORDER_ID <- as.numeric(as.character(df$ORDER_ID))
TOTALSALES <- df %>%
select(ORDER_ID,DATE,SALES) %>%
mutate(weekday = wday(DATE, label=TRUE)) %>%
mutate(DATE=as.Date(DATE)) %>%
filter(!wday(DATE) %in% c(1, 7) & !(DATE %in% as.Date(c('2017-01-02','2017-02-27','2017-02-28','2017-04-14'))) ) %>%
group_by(day=floor_date(DATE,"day")) %>%
summarise(sales=sum(SALES)) %>%
data.frame()
TOTALSALES$day <- TOTALSALES$day %>%
as.POSIXlt(, tz="America/Sao_Paulo") %>%
format("%d/%m/%Y")
TOTALSALES$sales <- TOTALSALES$sales %>%
format(digits=9, decimal.mark=",",nsmall=2,big.mark = ".")
TOTALSALES$day <- as.Date(df$DATE, format = "%d/%m/%Y")
Any idea how can I solve this problem or a direction on how it should be done ?
Appreciate any help

Answer 1

I'm not sure I understand your question.
To print a Date object in a particular date-time format you can use format
# This *converts* a character vector/factor to a vector of Dates
df$DATE <- as.Date(df$DATE, format = "%Y-%m-%d")
# This *prints* the Date vector as a character vector with format "%d/%m/%Y"
format(df$DATE, format = "%d/%m/%Y")
Minimal example
ss <- c("2017-09-04","2017-09-05")
date <- as.Date(ss, format = "%Y-%m-%d")
format(date, format = "%d/%m/%Y")
#[1] "04/09/2017" "05/09/2017"