# Make Dealing with Dates a Little Easier

## Documentation for package ‘lubridate’ version 1.9.4

- DESCRIPTION file.
- User guides, package vignettes and other documentation.
- Package NEWS.

## Help Pages

A C D E F G H I L M N O P Q R S T U W Y misc

## -- A --

add_with_rollback | Add and subtract months to a date without exceeding the last day of the new month
am | Does date time occur in the am or pm?
as.duration | Change an object to a duration
as.duration-method | Change an object to a duration
as.interval | Change an object to an 'interval'
as.interval-method | Change an object to an 'interval'
as.period | Change an object to a period
as.period-method | Change an object to a period
as_date | Convert an object to a date or date-time
as_date-method | Convert an object to a date or date-time
as_datetime | Convert an object to a date or date-time
as_datetime-method | Convert an object to a date or date-time

## -- C --

ceiling_date | Round, floor and ceiling methods for date-time objects
cyclic_encoding | Cyclic encoding of date-times

## -- D --

Date | Various date utilities
date | Get/set date component of a date-time
date<- | Get/set date component of a date-time
DateTimeUpdate | Changes the components of a date object
date_decimal | Converts a decimal to a date
day | Get/set days component of a date-time
day<- | Get/set days component of a date-time
days | Create or parse period objects
days_in_month | Get the number of days in the month of a date-time
ddays | Create a duration object.
decimal_date | Converts a date to a decimal of its year
dhours | Create a duration object.
dmicroseconds | Create a duration object.
dmilliseconds | Create a duration object.
dminutes | Create a duration object.
dmonths | Create a duration object.
dmy | Parse dates with *y*ear, *m*onth, and *d*ay components
dmy_h | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
dmy_hm | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
dmy_hms | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
dnanoseconds | Create a duration object.
dpicoseconds | Create a duration object.
dseconds | Create a duration object.
dst | Get *d*aylight *s*avings *t*ime indicator of a date-time
duration | Create a duration object.
Duration-class | Duration class
durations | Duration class
dweeks | Create a duration object.
dyears | Create a duration object.
dym | Parse dates with *y*ear, *m*onth, and *d*ay components

## -- E --

epiweek | Get/set weeks component of a date-time
epiyear | Get/set years component of a date-time

## -- F --

fast_strptime | User friendly date-time parsing functions
fit_to_timeline | Fit a POSIXlt date-time to the timeline
floor_date | Round, floor and ceiling methods for date-time objects
force_tz | Replace time zone to create new date-time
force_tz.default | Replace time zone to create new date-time
force_tzs | Replace time zone to create new date-time
format_ISO8601 | Format in ISO8601 character format
format_ISO8601-method | Format in ISO8601 character format

## -- G --

guess_formats | Guess possible date-times formats from a character vector

## -- H --

hm | Parse periods with *h*our, *m*inute, and *s*econd components
hms | Parse periods with *h*our, *m*inute, and *s*econd components
hour | Get/set hours component of a date-time
hour<- | Get/set hours component of a date-time
hours | Create or parse period objects

## -- I --

instant | Is x a date-time object?
instants | Is x a date-time object?
interval | Utilities for creation and manipulation of 'Interval' objects
Interval-class | Interval class
intervals | Interval class
int_aligns | Utilities for creation and manipulation of 'Interval' objects
int_diff | Utilities for creation and manipulation of 'Interval' objects
int_end | Utilities for creation and manipulation of 'Interval' objects
int_end<- | Utilities for creation and manipulation of 'Interval' objects
int_flip | Utilities for creation and manipulation of 'Interval' objects
int_length | Utilities for creation and manipulation of 'Interval' objects
int_overlaps | Utilities for creation and manipulation of 'Interval' objects
int_shift | Utilities for creation and manipulation of 'Interval' objects
int_standardize | Utilities for creation and manipulation of 'Interval' objects
int_start | Utilities for creation and manipulation of 'Interval' objects
int_start<- | Utilities for creation and manipulation of 'Interval' objects
is.Date | Various date utilities
is.difftime | Is x a difftime object?
is.duration | Create a duration object.
is.instant | Is x a date-time object?
is.interval | Utilities for creation and manipulation of 'Interval' objects
is.period | Create or parse period objects
is.POSIXct | Various POSIX utilities
is.POSIXlt | Various POSIX utilities
is.POSIXt | Various POSIX utilities
is.timepoint | Is x a date-time object?
is.timespan | Is x a length of time?
isoweek | Get/set weeks component of a date-time
isoyear | Get/set years component of a date-time

## -- L --

lakers | Lakers 2008-2009 basketball data set
leap_year | Is a year a leap year?
local_time | Get local time from a date-time vector.

## -- M --

m+ | Add and subtract months to a date without exceeding the last day of the new month
m- | Add and subtract months to a date without exceeding the last day of the new month
make_date | Efficient creation of date-times from numeric representations
make_datetime | Efficient creation of date-times from numeric representations
make_difftime | Create a difftime object.
mday | Get/set days component of a date-time
mday<- | Get/set days component of a date-time
mdy | Parse dates with *y*ear, *m*onth, and *d*ay components
mdy_h | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
mdy_hm | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
mdy_hms | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
microseconds | Create or parse period objects
milliseconds | Create or parse period objects
minute | Get/set minutes component of a date-time
minute<- | Get/set minutes component of a date-time
minutes | Create or parse period objects
month | Get/set months component of a date-time
month<- | Get/set months component of a date-time
months.numeric | Create or parse period objects
ms | Parse periods with *h*our, *m*inute, and *s*econd components
my | Parse dates with *y*ear, *m*onth, and *d*ay components
myd | Parse dates with *y*ear, *m*onth, and *d*ay components

## -- N --

nanoseconds | Create or parse period objects
NA_Date_ | Various date utilities
NA_POSIXct_ | Various POSIX utilities
now | The current day and time

## -- O --

origin | 1970-01-01 UTC

## -- P --

parse_date_time | User friendly date-time parsing functions
parse_date_time2 | User friendly date-time parsing functions
period | Create or parse period objects
periods | Create or parse period objects
period_to_seconds | Contrive a period to/from a given number of seconds
picoseconds | Create or parse period objects
pm | Does date time occur in the am or pm?
POSIXct | Various POSIX utilities
pretty_dates | Computes attractive axis breaks for date-time data

## -- Q --

qday | Get/set days component of a date-time
qday<- | Get/set days component of a date-time
quarter | Get the fiscal quarter and semester of a date-time

## -- R --

rollback | Roll backward or forward a date the previous, current or next month
rollbackward | Roll backward or forward a date the previous, current or next month
rollforward | Roll backward or forward a date the previous, current or next month
round_date | Round, floor and ceiling methods for date-time objects

## -- S --

second | Get/set seconds component of a date-time
second<- | Get/set seconds component of a date-time
seconds | Create or parse period objects
seconds_to_period | Contrive a period to/from a given number of seconds
semester | Get the fiscal quarter and semester of a date-time
stamp | Format dates and times based on human-friendly templates
stamp_date | Format dates and times based on human-friendly templates
stamp_time | Format dates and times based on human-friendly templates

## -- T --

timespan | Description of time span classes in lubridate
timespans | Description of time span classes in lubridate
time_length | Compute the exact length of a time span
time_length-method | Compute the exact length of a time span
today | The current day and time
tz | Get/set time zone component of a date-time
tz<- | Get/set time zone component of a date-time

## -- U --

update.POSIXt | Changes the components of a date object

## -- W --

wday | Get/set days component of a date-time
wday<- | Get/set days component of a date-time
week | Get/set weeks component of a date-time
week<- | Get/set weeks component of a date-time
weeks | Create or parse period objects
with_tz | Get date-time in a different time zone
with_tz.default | Get date-time in a different time zone

## -- Y --

yday | Get/set days component of a date-time
yday<- | Get/set days component of a date-time
ydm | Parse dates with *y*ear, *m*onth, and *d*ay components
ydm_h | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
ydm_hm | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
ydm_hms | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
year | Get/set years component of a date-time
year<- | Get/set years component of a date-time
years | Create or parse period objects
ym | Parse dates with *y*ear, *m*onth, and *d*ay components
ymd | Parse dates with *y*ear, *m*onth, and *d*ay components
ymd_h | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
ymd_hm | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
ymd_hms | Parse date-times with *y*ear, *m*onth, and *d*ay, *h*our, *m*inute, and *s*econd components.
yq | Parse dates with *y*ear, *m*onth, and *d*ay components

## -- misc --

%--% | Utilities for creation and manipulation of 'Interval' objects
%m+% | Add and subtract months to a date without exceeding the last day of the new month
%m+%-method | Add and subtract months to a date without exceeding the last day of the new month
%m-% | Add and subtract months to a date without exceeding the last day of the new month
%m-%-method | Add and subtract months to a date without exceeding the last day of the new month
%within% | Does a date (or interval) fall within an interval?
%within%-method | Does a date (or interval) fall within an interval?