Date-time data can be frustrating to work with in R. R commands for date-times are generally unintuitive and change depending on the type of date-time object being used. Moreover, the methods we use with date-times must be robust to time zones, leap days, daylight savings times, and other time related quirks, and R lacks these capabilities in some situations. Lubridate makes it easier to do the things R does with date-times and possible to do the things R does not.
If you are new to lubridate, the best place to start is the date and times chapter in R for data science.
# The easiest way to get lubridate is to install the whole tidyverse:
install.packages("tidyverse")
# Alternatively, install just lubridate:
install.packages("lubridate")
# Or the the development version from GitHub:
# install.packages("devtools")
devtools::install_github("tidyverse/lubridate")
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Easy and fast parsing of date-times:
ymd(),ymd_hms,dmy(),dmy_hms,mdy(), …ymd(20101215) #> [1] "2010-12-15" mdy("4/1/17") #> [1] "2017-04-01"
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Simple functions to get and set components of a date-time, such as
year(),month(),mday(),hour(),minute()andsecond():bday <- dmy("14/10/1979") month(bday) #> [1] 10 wday(bday, label = TRUE) #> [1] Sun #> Levels: Sun < Mon < Tue < Wed < Thu < Fri < Sat year(bday) <- 2016 wday(bday, label = TRUE) #> [1] Fri #> Levels: Sun < Mon < Tue < Wed < Thu < Fri < Sat
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Helper functions for handling time zones:
with_tz(),force_tz()time <- ymd_hms("2010-12-13 15:30:30") time #> [1] "2010-12-13 15:30:30 UTC" # Changes printing with_tz(time, "America/Chicago") #> [1] "2010-12-13 09:30:30 CST" # Changes time force_tz(time, "America/Chicago") #> [1] "2010-12-13 15:30:30 CST"
Lubridate also expands the type of mathematical operations that can be performed with date-time objects. It introduces three new time span classes borrowed from http://joda.org.
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durations, which measure the exact amount of time between two points -
periods, which accurately track clock times despite leap years, leap seconds, and day light savings time -
intervals, a protean summary of the time information between two points