1. What is lubridate and why would you use it?

• it’s an R package that makes working with dates easy

• because in base R working with dates may be a little bit daunting

• the only disadvantage is performance, so use it for small datasets only

2. A few “Hello World” examples

Load the package

library(lubridate)

## Warning in system("timedatectl", intern = TRUE): running command 'timedatectl'
## had status 1

Convert a string to class Date:

# the base way
d <- as.Date("2017-03-03")
class(d)

## [1] "Date"

# the lubridate way
d <- ymd("2017-03-03")
class(d)

## [1] "Date"

Extract year, month and day

year(d)

## [1] 2017

month(d)

## [1] 3

day(d)

## [1] 3

You can also modify the date on the fly:

year(d) <- 1410
month(d) <- 7
day(d) <- 15
print(d)

## [1] "1410-07-15"

class(d)

## [1] "Date"

now, the same as datetime.now() in Python’s datetime package:

# the base way
n <- Sys.time()
# the lubridate way
n <- now()

Extracting hour, minute and second

hour(n)

## [1] 13

minute(n)

## [1] 42

second(n)

## [1] 24.31276

Days of the week

wday(d)  # numbering starts from Sunday! you can adjust it, have a look at ?wday

## [1] 1

Adding / subtracting dates:

print(d)

## [1] "1410-07-15"

d + years(1)  # yearS - plural form

## [1] "1411-07-15"

d - months(2)

## [1] "1410-05-15"