install.packages("lubridate")

This release includes a range of bug fixes and minor improvements. Some highlights from this release include:

• period() and duration() constructors now accept character strings and allow a very flexible specification of timespans:

  period("3H 2M 1S")
  #> [1] "3H 2M 1S"
  
  duration("3 hours, 2 mins, 1 secs")
  #> [1] "10921s (~3.03 hours)"
  
  # Missing numerals default to 1. 
  # Repeated units are summed
  period("hour minute minute")
  #> [1] "1H 2M 0S"

  Period and duration parsing allows for arbitrary abbreviations of time units as long as the specification is unambiguous. For single letter specs, strptime() rules are followed, so m stands for months and M for minutes.

  These same rules allows you to compare strings and durations/periods:

  "2mins 1 sec" > period("2mins")
  #> [1] TRUE

• Date time rounding (with round_date(), floor_date() and ceiling_date()) now supports unit multipliers, like “3 days” or “2 months”:

  ceiling_date(ymd_hms("2016-09-12 17:10:00"), unit = "5 minutes")
  #> [1] "2016-09-12 17:10:00 UTC"

• The behavior of ceiling_date for Date objects is now more intuitive. In short, dates are now interpreted as time intervals that are physically part of longer unit intervals:

  |day1| ... |day31|day1| ... |day28| ...
  |    January     |   February     | ...

  That means that rounding up 2000-01-01 by a month is done to the boundary between January and February which, i.e. 2000-02-01:

  ceiling_date(ymd("2000-01-01"), unit = "month")
  #> [1] "2000-02-01"

  This behavior is controlled by the change_on_boundary argument.

• It is now possible to compare POSIXct and Date objects:

  ymd_hms("2000-01-01 00:00:01") > ymd("2000-01-01")
  #> [1] TRUE

• C-level parsing now handles English months and AM/PM indicator regardless of your locale. This means that English date-times are now always handled by lubridate C-level parsing and you don’t need to explicitly switch the locale.
• New parsing function yq() allows you to parse a year + quarter:

  yq("2016-02")
  #> [1] "2016-04-01"

  The new q format is available in all lubridate parsing functions.

See the release notes for the full list of changes. A big thanks goes to everyone who contributed: @arneschillert, @cderv, @ijlyttle, @jasonelaw, @jonboiser, and @krlmlr.