How to remove characters within a date in R

Question

I have a dataframe with a "Date" column, several thousand rows long. The dates are within their own cell, in this format:

2006-06-24

How can I get my "Date" column down to just the year, and then apply it to the rest of the rows? The dates change, and go through 2018. Thanks.

score 2 · Accepted Answer · answered Jun 24 '18 at 20:30

2

You can do this with sub and a regular expression.

Date = c("2006-06-24", "2007-07-25", "2008-08-26")
sub("(\\d{4})-.*", "\\1", Date)
[1] "2006" "2007" "2008"

answered Jun 24 '18 at 20:30

G5W

score 2 · Answer 2 · answered Jun 24 '18 at 20:44

2

If data is already in Date/POSIXct format then you can use format as:

# Sample data
v <- as.Date(c("2006-06-24","2006-06-25","2006-06-26"))

format(v,"%Y")
#[1] "2006" "2006" "2006"

answered Jun 24 '18 at 20:44

MKR

score 1 · Answer 3 · answered Jun 24 '18 at 20:43

1

Since you tagged dplyr, here's a tidyverse solution using lubridate::year():

library(lubridate)

dates <- c("2006-06-24", "2007-06-24")
year(dates)

[1] 2006 2007

answered Jun 24 '18 at 20:43

andrew_reece

3 Answers3