Numeric to date

[jynusmac]

I have a dataframe with one column in numeric format: 2022, 2021,2020, 2019....and more years

How can I convert it to year but with date format?

Thanks

[FJCC]

I am not sure what your goal is. A Date must have a month and a day. It is easy enough to assign a fixed day and month as in the following code.

DF <- data.frame(Year = c(2022, 2021, 2020), Value = 1:3)
str(DF)
'data.frame':	3 obs. of  2 variables:
 $ Year : num  2022 2021 2020
 $ Value: int  1 2 3

DF$Year <- as.Date(paste(DF$Year,"01-01", sep = "-"))

str(DF)
'data.frame':	3 obs. of  2 variables:
 $ Year : Date, format: "2022-01-01" "2021-01-01" ...
 $ Value: int  1 2 3

You cannot simultaneously have the value as a Date and display only the year value, if that is your goal.

[jynusmac]

Yes, I want to achieve only year, but this solution also works fine. Thanks!

[RichardJTelford]

You can use lubridate::make_date() to do this. For example

lubridate::make_date(year = 2020:2022)
# [1] "2020-01-01" "2021-01-01" "2022-01-01"

[jkatam]

Also try the unite() as below

year <- data.frame(year=c(2020:2022),month=1,day=1)
year2 <- year %>% unite(date,year,month,day,sep='-',remove = F) %>% mutate(date=as.Date(date))
str(year2)

'data.frame':	3 obs. of  4 variables:
 $ date : Date, format: "2020-01-01" "2021-01-01" "2022-01-01"
 $ year : int  2020 2021 2022
 $ month: num  1 1 1
 $ day  : num  1 1 1