Merge three different columns into a date in R

Question

Right now, I am having 3 separate columns as year, month, and day in a data file in R. How do I merge these three columns into just one column and make R understand that it

Answer 1

Or you could use the lubridate package, which makes working with dates and times in R much easier in general.

e.g.

df$date <- with(df, ymd(sprintf('%04d%02d%02d', year, mon, day)))
df$date
# [1] "1947-01-01 UTC" "1947-04-01 UTC" "1947-07-01 UTC" "1947-10-01 UTC"
# [5] "1948-01-01 UTC" "1948-04-01 UTC"

The ymd function takes a string representing Year, Month and Day, which could be "19470101", "1947-01-01", "1947/01/01", etc. Or there is also mdy and dmy if the elements are ordered differently. You can also optionally specify a time zone.