lubridate

Convert dd/mm/yy and dd/mm/yyyy to Dates

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You can use parse_date_time from lubridate: some.dates <- c(“23/11/12”, “20/10/2012”, “22/10/2012″ ,”23/11/12”) parse_date_time(some.dates,c(‘dmy’)) [1] “2012-11-23 UTC” “2012-10-20 UTC” “2012-10-22 UTC” “2012-11-23 UTC” But , Note that the order of format is important : some.dates <- c(“20/10/2012″,”23/11/12”, “22/10/2012″ ,”23/11/12”) parse_date_time(some.dates,c(‘dmY’,’dmy’)) [1] “2012-10-20 UTC” “2012-11-23 UTC” “2012-10-22 UTC” “2012-11-23 UTC” EDIT Internally parse_date_time is using guess_formats (which … Read more

Is there a more elegant way to convert two-digit years to four-digit years with lubridate?

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Here is a function that allows you to do this: library(lubridate) x <- mdy(c(“1/2/54″,”1/2/68″,”1/2/69″,”1/2/99″,”1/2/04”)) foo <- function(x, year=1968){ m <- year(x) %% 100 year(x) <- ifelse(m > year %% 100, 1900+m, 2000+m) x } Try it out: x [1] “2054-01-02 UTC” “2068-01-02 UTC” “1969-01-02 UTC” “1999-01-02 UTC” [5] “2004-01-02 UTC” foo(x) [1] “2054-01-02 UTC” “2068-01-02 … Read more

Generate a sequence of the last day of the month over two years

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Yes, you found the correct trick: going back a day from the first of the next month. Here is as a one-liner in base R: R> seq(as.Date(“2010-02-01″), length=24, by=”1 month”) – 1 [1] “2010-01-31” “2010-02-28” “2010-03-31” “2010-04-30” “2010-05-31” [6] “2010-06-30” “2010-07-31” “2010-08-31” “2010-09-30” “2010-10-31” [11] “2010-11-30” “2010-12-31” “2011-01-31” “2011-02-28” “2011-03-31” [16] “2011-04-30” “2011-05-31” “2011-06-30” “2011-07-31” … Read more

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