Year function in Lubridate is not only taking the year as planned

Question

I have been trying to use the year function in lubridate to extract only the year from a date, but it is still keeping the entire date. Can anyone help me fix this issue please?

        data %>% 
        select(ID, Author, Date, Location, Treatment) %>%     
        distinct() %>%
        drop_na() %>%   
        mutate(year = lubridate::year(Date)) %>% 
        unite('Study', Author, Date, Location, sep = " ", remove = T, na.rm = F) %>% 
        flextable() %>% 
        autofit()
  
           }

Answer 1

Your problem is that class(data$Dates) is a character column. It needs to be of class "Date" for year to understand which part is the year.

The default formats that as.Date check when passed a string are: c("%Y-%m-%d", "%Y/%m/%d"), which match the format your character column is in (e.g. YYYY-numeric month-day).

library(lubridate)
library(dplyr)

data %>% 
  mutate(year = year(as.Date(Dates)))

Output

       Dates year
1 1999-01-01 1999
2 1999-01-01 1999
3 1999-01-01 1999
4 1999-01-01 1999
5 1999-01-01 1999
6 1999-01-01 1999

Data

data <- structure(list(Dates = c("1999-01-01", "1999-01-01", "1999-01-01", 
"1999-01-01", "1999-01-01", "1999-01-01")), class = "data.frame", row.names = c(NA, 
-6L))