Cldr.Calendar behaviour (Cldr Calendars v1.13.0) View Source
Calendar functions for calendars compatible with
Elixir's Calendar
behaviour.
Cldr.Calendar
supports the creation of calendars
that are variations on the proleptic Cldr.Calendar.Gregorian
calendar. It also adds additional functions, defined
by the Cldr.Calendar
behaviour, to support these
derived calendars.
The common purpose of these derived calendars is to support the creation and use of financial year calendars that are commonly used in business.
There are two general types of calendars supported:
month
calendars that mirror the monthly structure of the proleptic Cldr.Calendar.Gregorian calendar but which are deemed to start the year in a month other than January.week
calendars that are defined to have a 52 week structure (53 weeks in a long year). These calendars can be configured to start or end on the first, last or nearest day to the beginning or end of a Cldr.Calendar.Gregorian month. The main intent behind this structure is to have each year start and end on the same day of the week with a consistent 13-week quarterly structure than enables a more straight forware comparison with same-period-last-year financial performance.
Link to this section Summary
Types
Specifies the type of a calendar.
Specifies the type of a calendar
Specifies the days of the week as integers.
The types of relationship between two Date.Range intervals
Represents the number of days since the calendar epoch.
The precision for date intervals
Specifies the quarter of year for a calendar date.
Specifies the week of year for a calendar date.
Functions
Returns a calendar configured according to the preferences defined for a locale.
Returns a calendar configured according to the preferences defined for a territory.
Return the calendar module for a locale.
Returns the calendar module preferred for a territory.
Returns a boolean indicating if a module
is a Cldr.Calendar
module
Returns the current date or date range for a date period (year, quarter, month, week or day).
Returns a date represented by a number of days since the start of the epoch.
Returns a Date.t
from a date tuple of
{year, month, day}
and a calendar.
Returns the number of days since the start of the epoch.
Formats a date into a string representation
Returns the {day_of_era, era}
for
a date
.
Returns the day
of the year
for a date
.
Returns the default calendar.
Returns the first day of a week for a given locale.
Returns the first date of a year
for a Date.t
.
Returns the first date of a year
in a calendar
.
Returns the gregorian date of the first day of of a year
for a calendar
.
Returns the ordinal day number representing Friday.
An inspect_fun/2
that can be configured in
Inspect.Opts
supporting inspection of user-defined
calendars.
Returns an Enumerable
list of dates of a given precision
of either :years
, :quarters
, :months
, :weeks
or
:days
Returns an a Stream
function than can be lazily
enumerated.
Returns the day of the week for a given
iso_day_number
Returns the ISO week
number for
a date
.
Returns the last date of a year
for a Date.t
.
Returns the last date of a year
for a calendar
.
Returns the gregorian date of the first day of a year
for a calendar
.
Returns a localized string for a part of
a Date.t
.
Returns the minimum days in the first week of a year for a given locale.
Decrements a date or date range by an integer amount of a date period (year, quarter, month, week or day).
Returns the Modified Julian Day of
a Date.t
.
Returns the ordinal day number representing Monday
Returns the month
number for
a date
.
Creates a new calendar based upon the provided configuration.
Returns the next date or date range for a date period (year, quarter, month, week or day).
Adds a duration to a date
Increments a date or date range by an integer amount of a date period (year, quarter, month, week or day).
Returns the previous date or date range for a date period (year, quarter, month, week or day).
Returns the quarter
number for
a date
.
Returns the ordinal day number representing Saturday.
Returns the ordinal day number representing Sunday.
Returns the ordinal day number representing Thursday.
Returns the ordinal day number representing Tuesday.
Validates if the argument is a Cldr.Calendar calendar module.
Returns the ordinal day number representing Wednesday.
Returns the {month, week_number}
for a date
.
Returns the {year, week_number}
for a date
.
Returns whether a given date is a weekday.
Returns a list of the days of the week that are considered a weekend for a given territory (country)
Returns a list of the days of the week that are considered a weekend for a given territory (country)
Returns whether a given date is a weekend day.
Returns the number of weeks in a year.
Returns the number of days in n
weeks
Callbacks
Returns the calendar basis.
Returns the CLDR calendar type.
Returns the number of days in a year
Returns a tuple of {year, week_in_year}
for a given year
, month
or week
, and day
for a a calendar.
Returns a date range representing the days in a given month for a calendar year.
Returns the month
for a given year
, month
or week
, and day
for a a calendar.
Returns the number of periods (which are months in a month calendar and weeks in a week calendar) in a year
Increments a Date.t
or Date.Range.t
by a specified positive
or negative integer number of periods (year, quarter, month,
week or day).
Returns a date range representing the days in a given quarter for a calendar year.
Returns a date range representing the days in a given week for a calendar year.
Returns a tuple of {month, week_in_month}
for a given year
, month
or week
, and day
for a a calendar.
Returns a tuple of {year, week_in_year}
for a given year
, month
or week
, and day
for a a calendar.
Returns the number of weeks in a year
Returns a date range representing the days in a calendar year.
Link to this section Types
Specs
calendar() :: module()
Specifies the type of a calendar.
A calendar is a module that implements
the Calendar
and Cldr.Calendar
behaviours.
Specs
calendar_type() :: :month | :week
Specifies the type of a calendar
Specs
day_of_week() :: 1..7
Specifies the days of the week as integers.
Days of the week are encoded as the integers 1
through
7
with 1
representig Monday and 7 representing Sunday.
Note that a calendar can be configured to start
on any day of the week. day_of_week
is only a
way of encoding the days as an integer.
Specs
interval_relation() :: :precedes | :preceded_by | :meets | :met_by | :overlaps | :overlapped_by | :finished_by | :finishes | :contains | :during | :starts | :started_by | :equals
The types of relationship between two Date.Range intervals
Specs
iso_day_number() :: integer()
Represents the number of days since the calendar epoch.
The Calendar epoch is 0000-01-01
in the proleptic gregorian calendar.
Specs
precision() :: :years | :quarters | :months | :weeks | :days
The precision for date intervals
Specs
quarter() :: 1..4
Specifies the quarter of year for a calendar date.
Specs
week() :: pos_integer()
Specifies the week of year for a calendar date.
Link to this section Functions
Returns a calendar configured according to the preferences defined for a locale.
Returns a calendar configured according to the preferences defined for a territory.
Return the calendar module for a locale.
Arguments
:locale
is any locale or locale name validated byCldr.validate_locale/2
. The default isCldr.get_locale()
which returns the locale set for the current process
Returns
{:ok, calendar_module}
or{:error, {exception, reason}}
Examples
iex> Cldr.Calendar.calendar_from_locale "en-US"
{:ok, Cldr.Calendar.US}
iex> Cldr.Calendar.calendar_from_locale "en-GB-u-ca-gregory"
{:ok, Cldr.Calendar.GB}
iex> Cldr.Calendar.calendar_from_locale "fa-IR"
{:ok, Cldr.Calendar.Persian}
iex> Cldr.Calendar.calendar_from_locale "fa-IR-u-ca-gregory"
{:ok, Cldr.Calendar.IR}
Returns the calendar module preferred for a territory.
Arguments
territory
is any valid ISO3166-2 code as anString.t
or upcasedatom()
Returns
{:ok, calendar_module}
or{:error, {exception, reason}}
Examples
iex> Cldr.Calendar.calendar_from_territory :US
{:ok, Cldr.Calendar.US}
iex> Cldr.Calendar.calendar_from_territory :XX
{:error, {Cldr.UnknownTerritoryError, "The territory :XX is unknown"}}
Notes
The overwhelming majority of territories have
:gregorian
as their first preferred calendar
and therefore Cldr.Calendar.Gregorian
or
a derivation of it will be returned for most
territories.
Returning any other calendar module would require:
That another calendar is preferred over
:gregorian
for a territoryThat a calendar module is available to support that calendar.
As an example, Iran (territory :IR
) prefers the
:persian
calendar. If the optional library
ex_cldr_calendars_persian
is installed, the calendar module Cldr.Calendar.Persian
will
be returned. If it is not installed, Cldr.Calendar.Gregorian
will be returned as :gregorian
is the second preference
for :IR
.
Returns a boolean indicating if a module
is a Cldr.Calendar
module
Returns the current date or date range for a date period (year, quarter, month, week or day).
Arguments
date_or_date_range
is anyDate.t
orDate.Range.t
period
is:year
,:quarter
,:month
,:week
or:day
Returns
When a Date.t
is passed, a Date.t
is
returned. When a Date.Range.t
is passed
a Date.Range.t
is returned.
Examples
iex> Cldr.Calendar.current ~D[2019-01-01], :day
~D[2019-01-01]
Specs
date_from_iso_days(Calendar.iso_days() | iso_day_number(), calendar()) :: Date.t()
Returns a date represented by a number of days since the start of the epoch.
The start of the epoch is the date
0000-01-01
.
Argumenets
iso_days
is an integer representing the number of days since the start of the epoch.calendar
is any module that implements theCalendar
andCldr.Calendar
behaviours
Returns
- a
Date.t()
Example
iex> Cldr.Calendar.date_from_iso_days 737425, Calendar.ISO
~D[2019-01-01]
iex> Cldr.Calendar.date_from_iso_days 366, Calendar.ISO
~D[0001-01-01]
iex> Cldr.Calendar.date_from_iso_days 0, Calendar.ISO
~D[0000-01-01]
Returns a Date.t
from a date tuple of
{year, month, day}
and a calendar.
Arguments
{year, month, day}
is a tuple representing a datecalendar
is any module implementing theCalendar
andCldr.Calendar
behaviours
Returns
- a
Date.t
Examples
iex> Cldr.Calendar.date_from_tuple {2019, 3, 25}, Cldr.Calendar.Gregorian
%Date{calendar: Cldr.Calendar.Gregorian, day: 25, month: 3, year: 2019}
iex> Cldr.Calendar.date_from_tuple {2019, 2, 29}, Cldr.Calendar.Gregorian
{:error, :invalid_date}
Specs
date_to_iso_days(Date.t()) :: iso_day_number()
Returns the number of days since the start of the epoch.
The start of the epoch is the date 0000-01-01.
Argumenets
date
is anyDate.t()
Returns
- The integer number of days since the epoch
for the given
date
.
Example
iex> Cldr.Calendar.date_to_iso_days ~D[2019-01-01]
737425
iex> Cldr.Calendar.date_to_iso_days ~D[0001-01-01]
366
iex> Cldr.Calendar.date_to_iso_days ~D[0000-01-01]
0
Specs
Formats a date into a string representation
Note that the output is not decorated with the calendar module name.
Example
iex> Cldr.Calendar.date_to_string ~D[2019-12-04]
"2019-12-04"
iex> Cldr.Calendar.date_to_string ~D[2019-23-04 Cldr.Calendar.NRF]
"2019-W23-4"
Specs
day_of_era(Date.t()) :: {Calendar.day(), Calendar.era()}
Returns the {day_of_era, era}
for
a date
.
Arguments
date
is anyDate.t()
Returns
- a the days since the start of the era and the era of the year as a tuple
Examples
iex> Cldr.Calendar.day_of_era ~D[2019-01-01]
{737060, 1}
iex> Cldr.Calendar.day_of_era Cldr.Calendar.first_day_of_year(2019, Cldr.Calendar.NRF)
{737093, 1}
iex> Cldr.Calendar.day_of_era Cldr.Calendar.last_day_of_year(2019, Cldr.Calendar.NRF)
{737456, 1}
See Date.day_of_week/1
.
Specs
day_of_year(Date.t()) :: Calendar.day()
Returns the day
of the year
for a date
.
Arguments
date
is anyDate.t()
Returns
- a the day of the year as an integer
Examples
iex> Cldr.Calendar.day_of_year ~D[2019-01-01]
1
iex> Cldr.Calendar.day_of_year ~D[2016-12-31]
366
iex> Cldr.Calendar.day_of_year ~D[2019-12-31]
365
iex> Cldr.Calendar.day_of_year ~D[2019-52-07 Cldr.Calendar.NRF]
365
iex> Cldr.Calendar.day_of_year ~D[2012-53-07 Cldr.Calendar.NRF]
372
See Date.days_in_month/1
.
Returns the default calendar.
Returns the first day of a week for a given locale.
Note that the first of the first week is commonly not aligned with the first day of the year.
Specs
Returns the first date of a year
for a Date.t
.
Arguments
date
is anyDate.t()
Returns
a
Date.t()
or{:error, :invalid_date}
Examples
iex> Cldr.Calendar.first_day_of_year ~D[2019-12-01]
~D[2019-01-01]
Specs
first_day_of_year(year :: Calendar.year(), calendar :: calendar()) :: Date.t()
Returns the first date of a year
in a calendar
.
Arguments
year
is any yearcalendar
is any module that implements theCalendar
andCldr.Calendar
behaviours
Returns
a
Date.t()
or{:error, :invalid_date}
Examples
iex> Cldr.Calendar.first_day_of_year 2019, Cldr.Calendar.Gregorian
%Date{calendar: Cldr.Calendar.Gregorian, day: 1, month: 1, year: 2019}
iex> Cldr.Calendar.first_day_of_year 2019, Cldr.Calendar.NRF
%Date{calendar: Cldr.Calendar.NRF, day: 1, month: 1, year: 2019}
Specs
first_gregorian_day_of_year(Calendar.year(), calendar()) :: Date.t() | {:error, :invalid_date}
Returns the gregorian date of the first day of of a year
for a calendar
.
Arguments
year
is any integer year numbercalendar
is any module that implements theCalendar
andCldr.Calendar
behaviours orCalendar.ISO
Examples
iex> Cldr.Calendar.first_gregorian_day_of_year 2019, Cldr.Calendar.Gregorian
%Date{calendar: Cldr.Calendar.Gregorian, day: 1, month: 1, year: 2019}
iex> Cldr.Calendar.first_gregorian_day_of_year 2019, Cldr.Calendar.NRF
%Date{calendar: Cldr.Calendar.Gregorian, day: 3, month: 2, year: 2019}
iex> Cldr.Calendar.first_gregorian_day_of_year ~D[2019-12-01]
~D[2019-01-01]
Specs
friday() :: 5
Returns the ordinal day number representing Friday.
Specs
inspect(term(), list()) :: Inspect.Algebra.t()
An inspect_fun/2
that can be configured in
Inspect.Opts
supporting inspection of user-defined
calendars.
This function can be configured in IEx
for Elixir version 1.9
and later by:
IEx.configure(inspect: [inspect_fun: &Cldr.Calendar.inspect/2])
:ok
Specs
interval( date_from :: Date.t(), date_to_or_count :: Date.t() | non_neg_integer(), precision() ) :: [Date.t()]
Returns an Enumerable
list of dates of a given precision
of either :years
, :quarters
, :months
, :weeks
or
:days
Arguments
date_from
is a anyDate.t
that is the start of the sequencedate_to_or_count
is upper bound of the sequence as aDate.t
or the number of dates in the sequence to be generatedprecision
is one of:years
,:quarters
,:months
,:weeks
or:days
The sequence is generated starting with date_from
until the next date
in the sequence would be after date_to
.
Notes
The sequence can be in ascending or descending date order
based upon whether date_from
is greater than date_to
.
Returns
- A list of dates
Examples
iex> d = ~D[2019-01-31]
~D[2019-01-31]
iex> d2 = ~D[2019-05-31]
~D[2019-05-31]
iex> Cldr.Calendar.interval d, 3, :months
[~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31]]
iex> Cldr.Calendar.interval d, d2, :months
[~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31],
~D[2019-04-30], ~D[2019-05-31]]
Specs
interval_stream( date_from :: Date.t(), date_to_or_count :: Date.t() | non_neg_integer(), precision() ) :: (... -> any())
Returns an a Stream
function than can be lazily
enumerated.
This function has the same arguments and provides
the same functionality as interval/3
exept that
it is lazily evaluated.
Arguments
date_from
is a anyDate.t
that is the start of the sequencedate_to_or_count
is upper bound of the sequence as aDate.t
or the number of dates in the sequence to be generatedprecision
is one of:years
,:quarters
,:months
,:weeks
or:days
The sequence is generated starting with date_from
until the next date
in the sequence would be after date_to
.
Notes
The sequence can be in ascending or descending date order
based upon whether date_from
is greater than date_to
.
Returns
- A list of dates
Examples
iex> d = ~D[2019-01-31]
~D[2019-01-31]
iex> d2 = ~D[2019-05-31]
~D[2019-05-31]
iex> Cldr.Calendar.interval_stream(d, 3, :months) |> Enum.to_list
[~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31]]
iex> Cldr.Calendar.interval_stream(d, d2, :months) |> Enum.to_list
[~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31],
~D[2019-04-30], ~D[2019-05-31]]
Specs
iso_days_to_day_of_week(Calendar.iso_days() | Calendar.day()) :: day_of_week()
Returns the day of the week for a given
iso_day_number
Arguments
iso_day_number
is the number of days since the start of the epoch. SeeCldr.Calendar.date_to_iso_days/1
Returns
- An integer representing a day of the week where Monday
is represented by
1
and Sunday is represented by7
Examples
iex> days = Cldr.Calendar.date_to_iso_days ~D[2019-01-01]
iex> Cldr.Calendar.iso_days_to_day_of_week(days) == Cldr.Calendar.tuesday
true
Specs
iso_week_of_year(Date.t()) :: {Calendar.year(), week()}
Returns the ISO week
number for
a date
.
Arguments
date
is anyDate.t()
Returns
a the ISO week of the year as an integer or
{:error, :not_defined}
is the calendar does not support the concept of weeks.
Examples
iex> Cldr.Calendar.iso_week_of_year ~D[2019-01-01]
{2019, 1}
iex> Cldr.Calendar.iso_week_of_year ~D[2019-02-01]
{2019, 5}
iex> Cldr.Calendar.iso_week_of_year ~D[2019-52-01 Cldr.Calendar.NRF]
{2020, 4}
iex> Cldr.Calendar.iso_week_of_year ~D[2019-26-01 Cldr.Calendar.NRF]
{2019, 30}
iex> Cldr.Calendar.iso_week_of_year ~D[2019-12-01 Cldr.Calendar.Julian]
{:error, :not_defined}
Specs
Returns the last date of a year
for a Date.t
.
Arguments
date
is anyDate.t()
Returns
a
Date.t()
or{:error, :invalid_date}
Examples
iex> Cldr.Calendar.last_day_of_year ~D[2019-01-01]
~D[2019-12-31]
Specs
last_day_of_year(year :: Calendar.year(), calendar :: calendar()) :: Date.t()
Returns the last date of a year
for a calendar
.
Arguments
year
is any yearcalendar
is any module that implements theCalendar
andCldr.Calendar
behaviours
Returns
a
Date.t()
or{:error, :invalid_date}
Examples
iex> Cldr.Calendar.last_day_of_year(2019, Cldr.Calendar.Gregorian)
%Date{calendar: Cldr.Calendar.Gregorian, day: 31, month: 12, year: 2019}
iex> Cldr.Calendar.last_day_of_year(2019, Cldr.Calendar.NRF)
%Date{calendar: Cldr.Calendar.NRF, day: 7, month: 52, year: 2019}
Specs
last_gregorian_day_of_year(Calendar.year(), calendar()) :: Date.t() | {:error, :invalid_date}
Returns the gregorian date of the first day of a year
for a calendar
.
Arguments
year
is any integer year numbercalendar
is any module that implements theCalendar
andCldr.Calendar
behaviours orCalendar.ISO
Examples
iex> Cldr.Calendar.last_gregorian_day_of_year 2019, Cldr.Calendar.Gregorian
%Date{calendar: Cldr.Calendar.Gregorian, day: 31, month: 12, year: 2019}
iex> Cldr.Calendar.last_gregorian_day_of_year 2019, Cldr.Calendar.NRF
%Date{calendar: Cldr.Calendar.Gregorian, day: 1, month: 2, year: 2020}
iex> Cldr.Calendar.last_gregorian_day_of_year ~D[2019-12-01]
~D[2019-12-31]
Specs
Returns a localized string for a part of
a Date.t
.
Arguments
date_
is anyDate.t
part
is one of:era
,:quarter
,:month
,:day_of_week
or:days_of_week
options
is a Keyword list of options
Options
:locale
is any valid locale name in the list returned byCldr.known_locale_names/1
or aCldr.LanguageTag
struct returned byCldr.Locale.new!/2
. The default isCldr.get_locale()
.backend
is any module that includesuse Cldr
and therefore is aCldr
backend module. The default isdefault_backend/0
.:format
is one of:wide
,:abbreviated
or:narrow
. The default is:abbreviated
.
Returns
A string representing the localized date part, or
A list of strings representing the days of the week for the part
:days_of_week
. The days are in week order for the given date's calendar{error, {exception_module, message}}
if an error is detected
Examples
iex> Cldr.Calendar.localize ~D[2019-01-01], :era
"AD"
iex> Cldr.Calendar.localize ~D[2019-01-01], :day_of_week
"Tue"
iex> Cldr.Calendar.localize ~D[0001-01-01], :day_of_week
"Mon"
iex> Cldr.Calendar.localize ~D[2019-01-01], :days_of_week
[{1, "Mon"}, {2, "Tue"}, {3, "Wed"}, {4, "Thu"}, {5, "Fri"}, {6, "Sat"}, {7, "Sun"}]
iex> Cldr.Calendar.localize ~D[2019-06-01], :era
"AD"
iex> Cldr.Calendar.localize ~D[2019-06-01], :quarter
"Q2"
iex> Cldr.Calendar.localize ~D[2019-06-01], :month
"Jun"
iex> Cldr.Calendar.localize ~D[2019-06-01], :day_of_week
"Sat"
iex> Cldr.Calendar.localize ~D[2019-06-01], :day_of_week, format: :wide
"Saturday"
iex> Cldr.Calendar.localize ~D[2019-06-01], :day_of_week, format: :narrow
"S"
iex> Cldr.Calendar.localize ~D[2019-06-01], :day_of_week, locale: "ar"
"السبت"
Returns the minimum days in the first week of a year for a given locale.
Decrements a date or date range by an integer amount of a date period (year, quarter, month, week or day).
Arguments
date_or_date_range
is anyDate.t
orDate.Range.t
period
is:year
,:quarter
,:month
,:week
or:day
options
is a Keyword list of options
Options
:coerce
is a boolean which, when set totrue
will coerce the month and/or day to be a valid date. This affects,for example, moving to the previous month from~D[2019-03-31]
. Sincce there is no date~D[2019-02-31]
this would normally return{:error, :invalid_date}
. Settingcoerce: true
it will return~D[2019-02-28]
.
Returns
When a Date.t
is passed, a Date.t
is
returned. When a Date.Range.t
is passed
a Date.Range.t
is returned.
Examples
iex> Cldr.Calendar.minus ~D[2016-03-01], :days, 1
~D[2016-02-29]
iex> Cldr.Calendar.minus ~D[2019-03-01], :months, 1
~D[2019-02-01]
iex> Cldr.Calendar.minus ~D[2016-03-01], :days, 1
~D[2016-02-29]
iex> Cldr.Calendar.minus ~D[2019-03-01], :days, 1
~D[2019-02-28]
iex> Cldr.Calendar.minus ~D[2019-03-01], :months, 1
~D[2019-02-01]
iex> Cldr.Calendar.minus ~D[2019-03-01], :quarters, 1
~D[2018-12-01]
iex> Cldr.Calendar.minus ~D[2019-03-01], :years, 1
~D[2018-03-01]
Returns the Modified Julian Day of
a Date.t
.
Arguments
date
is anyDate.t()
Returns
- an integer number representing the
Modified Julian Day of the
date
Notes
The Modified Julian Day is the number of days since November 17, 1858. Therefore this function only returns valid values for dates after this date.
Examples
iex> Cldr.Calendar.modified_julian_day ~D[2019-01-01]
58484
Specs
monday() :: 1
Returns the ordinal day number representing Monday
Specs
month_of_year(Date.t()) :: Calendar.month()
Returns the month
number for
a date
.
Arguments
date
is anyDate.t()
Returns
- a the quarter of the year as an integer
Examples
iex> Cldr.Calendar.month_of_year ~D[2019-01-01]
1
iex> Cldr.Calendar.month_of_year ~D[2019-12-01]
12
iex> Cldr.Calendar.month_of_year ~D[2019-52-01 Cldr.Calendar.NRF]
12
iex> Cldr.Calendar.month_of_year ~D[2019-26-01 Cldr.Calendar.NRF]
6
Specs
new(module(), calendar_type(), Keyword.t()) :: {:ok, calendar()} | {:module_already_exists, module()}
Creates a new calendar based upon the provided configuration.
If a module exists with the calendar_module
name then it
is returned, not recreated.
Arguments
calendar_module
is am atom representing the module name of the created calendar.calendar_type
is an atom of either:month
or:week
indicating whcih type of calendar is to be createdconfig
is a Keyword list defining the configuration of the calendar.
Returns
{:ok, module}
wheremodule
is the new calendar module that conforms to theCalendar
andCldr.Calendar
behaviours or{:module_already_exists, module}
if a module of the given calendar name already exists. It is not guaranteed that the module is in fact a calendar module in this case.
Configuration options
The following options can be provided to create a new calendar.
:cldr_backend
defines a default backend module to be used for this calendar. The default isnil
.:weeks_in_month
defines the layout of weeks in a quarter for a week- or month- based calendar. The value must be one of[4, 4, 5]
,[4,5,4]
or[5,4,4]
. The default is[4,4,5]
. This option is ignored for:month
based calendars that have the parameterday_of_year: :first
.:begins_or_ends
determines whether the calendar year begins or ends on the given:day_of_week
and:month_of_year
. The default is:begins
.:first_or_last
determines whether the calendar year starts (or ends) on the first, last or nearest:day-of_week
and:month_of_year
. The default is:first
:day_of_week
determines the day of the week on which this calendar begins or ends. It may be a number in the range1..7
representing Monday to Sunday. It may also be:first
indicating the the weeks are calculated from the first day of the calendar day irrespective of the day of the week. In this case the last week of the year may be less than 7 days in length. The default is1
.:month_of_year
determines the Cldr.Calendar.Gregorian month of year in which this calendar begins or ends. The default is1
.:year
is used to determine which calendar Greogian year is applicable for a given calendar date. The valid options are:first
,:last
andmajority
. The default is:majority
.:min_days_in_first_week
is used to determine how many days of the Cldr.Calendar.Gregorian year must be in the first week of a calendar year. This is used when determining when the year starts for week-based years. The default is4
which is consistent with the ISO Week calendar
Examples
Each calendar has a function __config__/0
generated within
it and therefore the configuraiton of the included calendars
in ex_cldr_calendars
provide insight into the behaviour
of the configuration parameters.
As an example here we define the ISO Week calendar calendar in full:
defmodule ISOWeek do
use Cldr.Calendar.Base.Week,
day_of_week: 1, # Weeks begin or end on Monday
month_of_year: 1, # Years begin or end in January
min_days_in_first_week, 4, # 4 Cldr.Calendar.Gregorian days of the year must be in the first week
begins_or_ends: :begins, # The year *begins* on the `day_of_week` and `month_of_year`
first_or_last: :first, # They year *begins* on the *first* `day_of_week` and `month_of_year`
weeks_in_month: [4, 5, 4], # The weeks are laid out as *months* in a `[4,5,4]` pattern
year: :majority, # Any given year is that in which the majority of Cldr.Calendar.Gregorian months fall
cldr_backend: nil, # No default `cldr_backend` is configured.
locale: nil # No `locale` is used to aid configuration
end
This can be generated at runtime by:
iex> Cldr.Calendar.new ISOWeek, :week,
...> day_of_week: 1,
...> month_of_year: 1,
...> min_days_in_first_week: 4,
...> begins_or_ends: :begins,
...> first_or_last: :first,
...> weeks_in_month: [4, 5, 4],
...> year: :majority,
...> cldr_backend: nil
{:ok, ISOWeek}
Note that Cldr.Calendar.ISOWeek
is included as part of this
library.
Returns the next date or date range for a date period (year, quarter, month, week or day).
Arguments
date_or_date_range
is anyDate.t
orDate.Range.t
period
is:year
,:quarter
,:month
,:week
or:day
Returns
When a Date.t
is passed, a Date.t
is
returned. When a Date.Range.t
is passed
a Date.Range.t
is returned.
Examples
iex> Cldr.Calendar.next ~D[2019-01-01], :day
~D[2019-01-02]
iex> Cldr.Calendar.next ~D[2019-01-01], :month
~D[2019-02-01]
iex> Cldr.Calendar.next ~D[2019-01-01], :quarter
~D[2019-04-01]
iex> Cldr.Calendar.next ~D[2019-01-01], :year
~D[2020-01-01]
Specs
plus(integer(), integer()) :: integer()
plus(Calendar.date(), Cldr.Calendar.Duration.t()) :: Calendar.date()
Adds a duration to a date
Arguments
date
is any map that conforms toCalendar.date()
duration
is any duration returned byCldr.Calendar.Duration.new!/2
options
is a Keyword list of options
Options
- Options are those applicatable to
Cldr.Calendar.plus/4
Returns
- A
date
advanced by the duration
Examples
iex> Cldr.Calendar.plus ~D[2020-01-01],
...> Cldr.Calendar.Duration.new!(~D[2020-01-01], ~D[2020-02-01])
~D[2020-02-01]
iex> Cldr.Calendar.plus ~D[2020-01-01],
...> Cldr.Calendar.Duration.new!(~D[2020-01-01], ~D[2020-01-02])
~D[2020-01-02]
iex> Cldr.Calendar.plus ~D[2020-01-01],
...> Cldr.Calendar.Duration.new!(~D[2020-01-01], ~D[2020-02-01])
~D[2020-02-01]
iex> Cldr.Calendar.plus ~D[2020-01-01],
...> Cldr.Calendar.Duration.new!(~D[2020-01-01], ~D[2021-02-01])
~D[2021-02-01]
Specs
plus(Calendar.date() | Date.Range.t(), atom(), integer(), Keyword.t()) :: Calendar.date()
Increments a date or date range by an integer amount of a date period (year, quarter, month, week or day).
Arguments
date_or_date_range
is anyDate.t
orDate.Range.t
period
is:year
,:quarter
,:month
,:week
or:day
options
is a Keyword list of options
Options
:coerce
is a boolean which, when set totrue
will coerce the month and/or day to be a valid date. This affects,for example, moving to the previous month from~D[2019-03-31]
. Sincce there is no date~D[2019-02-31]
this would normally return{:error, :invalid_date}
. Settingcoerce: true
it will return~D[2019-02-28]
.
Returns
When a Date.t
is passed, a Date.t
is
returned. When a Date.Range.t
is passed
a Date.Range.t
is returned.
Examples
iex> Cldr.Calendar.plus ~D[2016-02-29], :days, 1
~D[2016-03-01]
iex> Cldr.Calendar.plus ~D[2019-03-01], :months, 1
~D[2019-04-01]
iex> Cldr.Calendar.plus ~D[2016-02-29], :days, 1
~D[2016-03-01]
iex> Cldr.Calendar.plus ~D[2019-02-28], :days, 1
~D[2019-03-01]
iex> Cldr.Calendar.plus ~D[2019-03-01], :months, 1
~D[2019-04-01]
iex> Cldr.Calendar.plus ~D[2019-03-01], :quarters, 1
~D[2019-06-01]
iex> Cldr.Calendar.plus ~D[2019-03-01], :years, 1
~D[2020-03-01]
Returns the previous date or date range for a date period (year, quarter, month, week or day).
Arguments
date_or_date_range
is anyDate.t
orDate.Range.t
period
is:year
,:quarter
,:month
,:week
or:day
options
is a Keyword list of options that is passed toplus/4
orminus/4
Returns
When a Date.t
is passed, a Date.t
is
returned. When a Date.Range.t
is passed
a Date.Range.t
is returned.
Examples
iex> Cldr.Calendar.previous ~D[2019-01-01], :day
~D[2018-12-31]
iex> Cldr.Calendar.previous ~D[2019-01-01], :quarter
~D[2018-10-01]
iex> Cldr.Calendar.previous ~D[2019-01-01], :month
~D[2018-12-01]
iex> Cldr.Calendar.previous ~D[2019-01-01], :year
~D[2018-01-01]
Specs
Returns the quarter
number for
a date
.
Arguments
date
is anyDate.t()
Returns
- a the quarter of the year as an integer
Examples
iex> Cldr.Calendar.quarter_of_year ~D[2019-01-01]
1
iex> Cldr.Calendar.quarter_of_year Cldr.Calendar.first_day_of_year(2019, Cldr.Calendar.NRF)
1
iex> Cldr.Calendar.quarter_of_year Cldr.Calendar.last_day_of_year(2019, Cldr.Calendar.NRF)
4
Specs
saturday() :: 6
Returns the ordinal day number representing Saturday.
Specs
sunday() :: 7
Returns the ordinal day number representing Sunday.
Specs
thursday() :: 4
Returns the ordinal day number representing Thursday.
Specs
tuesday() :: 2
Returns the ordinal day number representing Tuesday.
Validates if the argument is a Cldr.Calendar calendar module.
Arguments
calendar_module
is a module that implements theCldr.Calendar
behaviour
Returns
{:ok, calendar_module}
or{:error, {exception, reason}}
Examples
iex> Cldr.Calendar.validate_calendar Cldr.Calendar.Gregorian
{:ok, Cldr.Calendar.Gregorian}
iex> Cldr.Calendar.validate_calendar :not_a_calendar
{:error,
{Cldr.InvalidCalendarModule, ":not_a_calendar is not a calendar module."}}
Specs
wednesday() :: 3
Returns the ordinal day number representing Wednesday.
Specs
week_of_month(Date.t()) :: {Calendar.month(), week()}
Returns the {month, week_number}
for a date
.
The nature of a week depends on the calendar configuration and therefore some results may be surprising. For example the date of December 31st 2018 is actually in month one of the ISO Week calendar of 2019.
Arguments
date
is anyDate.t()
Returns
a tuple of the form
{month, week}
or{:error, :not_defined}
if the calendar does not support the concept of weeks.
Examples
iex> Cldr.Calendar.week_of_month(~D[2019-01-01])
{1, 1}
iex> Cldr.Calendar.week_of_month(~D[2018-12-31])
{1, 1}
iex> Cldr.Calendar.week_of_month(~D[2019-01-01 Cldr.Calendar.BasicWeek])
{1, 1}
iex> Cldr.Calendar.week_of_month(~D[2018-12-31 Cldr.Calendar.BasicWeek])
{12, 5}
iex> Cldr.Calendar.week_of_month(~D[2018-12-31 Cldr.Calendar.Julian])
{:error, :not_defined}
Specs
week_of_year(Date.t()) :: {Calendar.year(), week()}
Returns the {year, week_number}
for a date
.
Arguments
date
is anyDate.t()
Returns
a the week of the year as an integer or
{:error, :not_defined}
if the calendar does not support the concept of weeks.
Examples
iex> Cldr.Calendar.week_of_year ~D[2019-01-01]
{2019, 1}
iex> Cldr.Calendar.week_of_year ~D[2019-12-01]
{2019, 48}
iex> Cldr.Calendar.week_of_year ~D[2019-52-01 Cldr.Calendar.NRF]
{2019, 52}
iex> Cldr.Calendar.week_of_year ~D[2019-26-01 Cldr.Calendar.NRF]
{2019, 26}
iex> Cldr.Calendar.week_of_year ~D[2019-12-01 Cldr.Calendar.Julian]
{:error, :not_defined}
Specs
Returns whether a given date is a weekday.
Weekdays are locale-specific and depend on the policies of a given territory (country).
Arguments
date
is anyDate.t()
options
is a Keyword list of options
Options
:locale
is any locale or locale name validated byCldr.validate_locale/2
. The default isCldr.get_locale()
which returns the locale set for the current process:territory
is any valid ISO-3166-2 territory that is validated byCldr.validate_territory/1
:backend
is anyCldr
backend module. See the backend configuration documentation for further information. The default isCldr.Calendar.Backend.Default
which configures only theen
locale.
Notes
When identifying which territory context within which to determine whether a given day is a weekday or not the following order applies:
A territory specified by the
:territory
optionThe territory defined as part of the
:locale
optionThe territory defined as part of the current processes default locale.
Examples
# The defalt locale for `Cldr` is `en-001` for which
# the territory is `001` (the world). The weekdays
# for `001` are Monday to Friday
iex> Cldr.Calendar.weekday? ~D[2019-03-23], locale: "en"
false
iex> Cldr.Calendar.weekday? ~D[2019-03-23], territory: "IS"
false
# Saturday is a weekday in India
iex> Cldr.Calendar.weekday? ~D[2019-03-23], locale: "en-IN", backend: MyApp.Cldr
true
# Friday is not a weekday in Saudi Arabia
iex> Cldr.Calendar.weekday? ~D[2019-03-22], locale: "ar-SA", backend: MyApp.Cldr
false
# Friday is not a weekday in Israel
iex> Cldr.Calendar.weekday? ~D[2019-03-22], locale: "he", backend: MyApp.Cldr
false
Returns a list of the days of the week that are considered a weekend for a given territory (country)
Arguments
territory
is any valid ISO3166-2 code
Returns
- A list of integers representing the days of the week that are week days
Notes
The list of days may not my monotonic. See the example for Saudi Arabia below.
Examples
iex> Cldr.Calendar.weekdays("US")
[1, 2, 3, 4, 5]
iex> Cldr.Calendar.weekdays("IN")
[1, 2, 3, 4, 5, 6]
iex> Cldr.Calendar.weekdays("SA")
[1, 2, 3, 4, 7]
iex> Cldr.Calendar.weekdays("xx")
{:error, {Cldr.UnknownTerritoryError, "The territory :XX is unknown"}}
Returns a list of the days of the week that are considered a weekend for a given territory (country)
Arguments
territory
is any valid ISO3166-2 code
Returns
- A list of integers representing the days of the week that are weekend days
Examples
iex> Cldr.Calendar.weekend("US")
[6, 7]
iex> Cldr.Calendar.weekend("IN")
[7]
iex> Cldr.Calendar.weekend("SA")
[5, 6]
iex> Cldr.Calendar.weekend("xx")
{:error, {Cldr.UnknownTerritoryError, "The territory :XX is unknown"}}
Specs
Returns whether a given date is a weekend day.
Weekend days are locale-specific and depend on the policies of a given territory (country).
Arguments
date
is anyDate.t()
options
is a Keyword list of options
Options
:locale
is any locale or locale name validated byCldr.validate_locale/2
. The default isCldr.get_locale()
which returns the locale set for the current process:territory
is any valid ISO-3166-2 territory that is validated byCldr.validate_territory/1
:backend
is anyCldr
backend module. See the backend configuration documentation for further information. The default isCldr.Calendar.Backend.Default
which configures only theen
locale.
Notes
When identifying which territory context within which to determine whether a given day is a weekend or not the following order applies:
A territory specified by the
:territory
optionThe territory defined as part of the
:locale
optionThe territory defined as part of the current processes default locale.
Examples
# The defalt locale for `Cldr` is `en-001` for which
# the territory is `001` (the world). The weekend
# for `001` is Saturday and Sunday
iex> Cldr.Calendar.weekend? ~D[2019-03-23]
true
iex> Cldr.Calendar.weekend? ~D[2019-03-23], locale: "en"
true
iex> Cldr.Calendar.weekend? ~D[2019-03-23], territory: "IS"
true
# In India the official weekend is only Sunday
iex> Cldr.Calendar.weekend? ~D[2019-03-23], locale: "en-IN", backend: MyApp.Cldr
false
# In Israel the weekend starts on Friday
iex> Cldr.Calendar.weekend? ~D[2019-03-22], locale: "he", backend: MyApp.Cldr
true
# As it also does in Saudia Arabia
iex> Cldr.Calendar.weekend? ~D[2019-03-22], locale: "ar-SA", backend: MyApp.Cldr
true
# Sunday is not a weekend day in Saudi Arabia
iex> Cldr.Calendar.weekend? ~D[2019-03-24], locale: "ar-SA", backend: MyApp.Cldr
false
Specs
Returns the number of weeks in a year.
Arguments
- Either a
Date.t()
or an integer year a calendar name
Returns
- In integer number of weeks in a year
Examples
iex> Cldr.Calendar.weeks_in_year ~D[2026-W01-1 Cldr.Calendar.ISOWeek]
53
iex> Cldr.Calendar.weeks_in_year ~D[2019-01-01]
52
iex> Cldr.Calendar.weeks_in_year ~D[2020-01-01]
52
iex> Cldr.Calendar.weeks_in_year 2020, Cldr.Calendar.ISOWeek
53
Specs
weeks_in_year(Calendar.year(), calendar()) :: week()
Specs
Returns the number of days in n
weeks
Example
iex> Cldr.Calendar.weeks_to_days(2)
14
Link to this section Callbacks
Specs
calendar_base() :: :week | :month
Returns the calendar basis.
Returns either :week or :month
Specs
cldr_calendar_type() :: :gregorian | :persian | :coptic | :ethiopic
Returns the CLDR calendar type.
Only algorithmic calendars are considered in this implementation
Specs
days_in_year(year :: Calendar.year()) :: Calendar.day()
Returns the number of days in a year
Specs
iso_week_of_year( year :: Calendar.year(), month :: Calendar.month(), day :: Calendar.day() ) :: {Calendar.year(), Calendar.week()} | {:error, :not_defined}
Returns a tuple of {year, week_in_year}
for a given year
, month
or week
, and day
for a a calendar.
The iso_week_of_year
is calculated based on the ISO calendar.
Specs
month(year :: Calendar.year(), month :: Calendar.month()) :: Date.Range.t()
Returns a date range representing the days in a given month for a calendar year.
Specs
month_of_year( year :: Calendar.year(), month :: Calendar.month() | week(), day :: Calendar.day() ) :: Calendar.month()
Returns the month
for a given year
, month
or week
, and day
for a a calendar.
The month_of_year
is calculated based upon the calendar configuration.
Specs
periods_in_year(year :: Calendar.year()) :: week() | Calendar.month()
Returns the number of periods (which are months in a month calendar and weeks in a week calendar) in a year
Specs
plus( year :: Calendar.year(), month :: Calendar.month() | week(), day :: Calendar.day(), months_or_quarters :: :months | :quarters, increment :: integer(), options :: Keyword.t() ) :: {Calendar.year(), Calendar.month(), Calendar.day()}
Increments a Date.t
or Date.Range.t
by a specified positive
or negative integer number of periods (year, quarter, month,
week or day).
Calendars need only implement this callback for :months
and :quarters
since all other date periods can be derived.
Specs
quarter(year :: Calendar.year(), quarter :: quarter()) :: Date.Range.t()
Returns a date range representing the days in a given quarter for a calendar year.
Specs
week(year :: Calendar.year(), week :: week()) :: Date.Range.t() | {:error, :not_defined}
Returns a date range representing the days in a given week for a calendar year.
Specs
week_of_month(Calendar.year(), week(), Calendar.day()) :: {Calendar.month(), week()} | {:error, :not_defined}
Returns a tuple of {month, week_in_month}
for a given year
, month
or week
, and day
for a a calendar.
The week_in_month
is calculated based upon the calendar configuration.
Specs
week_of_year( year :: Calendar.year(), month :: Calendar.month() | week(), day :: Calendar.day() ) :: {Calendar.year(), Calendar.week()} | {:error, :not_defined}
Returns a tuple of {year, week_in_year}
for a given year
, month
or week
, and day
for a a calendar.
The week_in_year
is calculated based upon the calendar configuration.
Specs
weeks_in_year(year :: Calendar.year()) :: week() | {:error, :not_defined}
Returns the number of weeks in a year
Specs
year(year :: Calendar.year()) :: Date.Range.t()
Returns a date range representing the days in a calendar year.