# `Calendrical` Calendar functions for calendars compatible with Elixir's `Calendar` behaviour. `Calendrical` supports the creation of calendars that are variations on the proleptic Calendrical.Gregorian calendar. It also adds additional functions, defined by the `Calendrical` 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 `Calendrical.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 `Calendrical.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. # `any_date_time` ```elixir @type any_date_time() :: date() | time() | naive_date_time() | date_time() ``` Super type of any date or time. # `calendar` ```elixir @type calendar() :: module() | nil ``` Specifies the type of a calendar. A calendar is a module that implements the `Calendar` and `Calendrical` behaviours. Calendar functions will default to `Calendrical.Gregorian` in most cases. # `calendar_type` ```elixir @type calendar_type() :: :month | :week ``` Specifies the type of a calendar # `date` ```elixir @type date() :: %{ optional(:year) => year(), optional(:month) => month(), optional(:day) => day(), optional(:calendar) => calendar(), optional(any()) => any() } ``` All date fields are optional however many functions will require the presence of one or more - and often all - fields be present. # `date_time` ```elixir @type date_time() :: %{ optional(:calendar) => calendar(), optional(:day) => day(), optional(:hour) => Calendar.hour(), optional(:microsecond) => Calendar.microsecond(), optional(:minute) => Calendar.minute(), optional(:month) => month(), optional(:second) => Calendar.second(), optional(:std_offset) => Calendar.std_offset(), optional(:time_zone) => Calendar.time_zone(), optional(:utc_offset) => Calendar.utc_offset(), optional(:year) => year(), optional(:zone_abbr) => Calendar.zone_abbr(), optional(any()) => any() } ``` All date time fields are optional however many functions will require the presence of one or more - and often all - fields be present. # `day` ```elixir @type day() :: Calendar.day() | nil ``` Specifies the day of a date as either a positive integer or nil. # `day_of_week` ```elixir @type 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` representing 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. # `day_of_week_to_binary` ```elixir @type day_of_week_to_binary() :: {day_of_week(), String.t()} ``` A mapping of a day of the week ordinal to the localized string of the name of that day. # `era` ```elixir @type era() :: non_neg_integer() | nil ``` Specifies the year of a date as either a positive integer or nil. # `interval_relation` ```elixir @type 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 # `iso_day_number` ```elixir @type 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. # `leap_month?` ```elixir @type leap_month?() :: boolean() ``` Boolean indicating is this is a leap month # `month` ```elixir @type month() :: Calendar.month() | nil ``` Specifies the month of a date as either a positive integer or nil. # `naive_date_time` ```elixir @type naive_date_time() :: %{ optional(:calendar) => calendar(), optional(:day) => day(), optional(:hour) => Calendar.hour(), optional(:microsecond) => Calendar.microsecond(), optional(:minute) => Calendar.minute(), optional(:month) => month(), optional(:second) => Calendar.second(), optional(:year) => year(), optional(any()) => any() } ``` All naive date time fields are optional however many functions will require the presence of one or more - and often all - fields be present. # `part` ```elixir @type part() :: :day_periods | :am_pm | :days_of_week | :day_of_week | :month | :quarter | :era ``` The part of a date, time or datetime that can be localized. # `precision` ```elixir @type precision() :: :years | :quarters | :months | :weeks | :days ``` The precision for date intervals # `quarter` ```elixir @type quarter() :: 1..4 ``` Specifies the quarter of year for a calendar date. # `time` ```elixir @type time() :: %{ optional(:calendar) => Calendar.calendar(), optional(:hour) => Calendar.hour(), optional(:microsecond) => Calendar.microsecond(), optional(:minute) => Calendar.minute(), optional(:second) => Calendar.second(), optional(any()) => any() } ``` All time fields are optional however many functions will require the presence of one or more - and often all - fields be present. # `week` ```elixir @type week() :: pos_integer() ``` Specifies the week of year for a calendar date. # `year` ```elixir @type year() :: Calendar.year() | nil ``` Specifies the year of a date as either a positive integer or nil. # `calendar_base` ```elixir @callback calendar_base() :: :week | :month ``` Returns the calendar basis. Returns either `:week` or `:month`. # `calendar_year` ```elixir @callback calendar_year(year :: year(), month :: month(), day :: day()) :: Calendar.year() ``` Returns a the year in a calendar year. # `cldr_calendar_type` ```elixir @callback cldr_calendar_type() :: :gregorian | :persian | :coptic | :ethiopic | :ethiopic_amete_alem | :chinese | :japanese | :dangi | :islamic | :islamic_civil | :islamic_rgsa | :islamic_tbla | :islamic_umalqura | :hebrew | :buddhist | :roc | :indian ``` Returns the CLDR calendar type. Only algorithmic calendars are considered in this implementation. # `cyclic_year` ```elixir @callback cyclic_year(year :: year(), month :: month(), day :: day()) :: Calendar.year() ``` Returns a the cyclic year in a calendar year. # `days_in_month` ```elixir @callback days_in_month(month :: month()) :: Calendar.day() | {:ambiguous, Range.t() | [pos_integer()]} | {:error, :undefined} ``` Returns the number of days in a month (withoout a year). # `days_in_year` ```elixir @callback days_in_year(year :: year()) :: Calendar.day() ``` Returns the number of days in a year. # `extended_year` ```elixir @callback extended_year(year :: year(), month :: month(), day :: day()) :: Calendar.year() ``` Returns a the extended year in a calendar year. # `iso_week_of_year` ```elixir @callback iso_week_of_year( year :: year(), month :: month() | week(), day :: 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. # `month` ```elixir @callback month(year :: year(), month :: month()) :: Date.Range.t() | {:error, :not_defined} ``` Returns a date range representing the days in a given month for a calendar year. # `month_of_year` ```elixir @callback month_of_year( year :: year(), month :: month() | week(), day :: day() ) :: Calendar.month() | {Calendar.month(), leap_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. # `periods_in_year` ```elixir @callback periods_in_year(year :: 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 # `plus` ```elixir @callback plus( year :: year(), month :: month() | week(), day :: day(), months_or_quarters :: :months | :quarters, increment :: integer(), options :: Keyword.t() ) :: {Calendar.year(), Calendar.month(), Calendar.day()} ``` Increments a `t:Calendar.date/0` or `t:Date.Range.t/0` 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. # `quarter` ```elixir @callback quarter(year :: year(), quarter :: quarter()) :: Date.Range.t() | {:error, :not_defined} ``` Returns a date range representing the days in a given quarter for a calendar year. # `related_gregorian_year` ```elixir @callback related_gregorian_year(year :: year(), month :: month(), day :: day()) :: Calendar.year() ``` Returns a the related year in a calendar year. # `week` ```elixir @callback week(year :: year(), week :: week()) :: Date.Range.t() | {:error, :not_defined} ``` Returns a date range representing the days in a given week for a calendar year. # `week_of_month` ```elixir @callback week_of_month(year(), week(), 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. # `week_of_year` ```elixir @callback week_of_year( year :: year(), month :: month() | week(), day :: 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. # `weeks_in_year` ```elixir @callback weeks_in_year(year :: year()) :: {week(), Calendar.day()} | {:error, :not_defined} ``` Returns the number of weeks in a year. # `year` ```elixir @callback year(year :: year()) :: Date.Range.t() | {:error, :not_defined} ``` Returns a date range representing the days in a calendar year. # `calendar_for_territory` Returns a calendar configured according to the preferences defined for a territory. # `calendar_from_cldr_calendar_type` ```elixir @spec calendar_from_cldr_calendar_type(atom() | String.t()) :: {:ok, module()} | {:error, Exception.t()} ``` Returns the Calendrical calendar module associated with a CLDR calendar type. CLDR calendar types are the atoms (or their string equivalents) returned by `Localize.validate_calendar/1` and listed by `supported_cldr_calendar_types/0`. This function maps such a type to the corresponding Calendrical calendar module if it is loaded in the current build. ### Arguments * `calendar_type` is a CLDR calendar type as an atom or string. The string `"gregory"` is accepted as an alias for `:gregorian`. ### Returns * `{:ok, calendar_module}` where `calendar_module` is the Calendrical calendar module for the given CLDR calendar type, or * `{:error, exception}` where `exception` is an exception struct. ### Examples iex> Calendrical.calendar_from_cldr_calendar_type(:gregorian) {:ok, Calendrical.Gregorian} iex> Calendrical.calendar_from_cldr_calendar_type("gregory") {:ok, Calendrical.Gregorian} iex> Calendrical.calendar_from_cldr_calendar_type(:persian) {:ok, Calendrical.Persian} iex> Calendrical.calendar_from_cldr_calendar_type(:islamic_umalqura) {:ok, Calendrical.Islamic.UmmAlQura} iex> Calendrical.calendar_from_cldr_calendar_type(:ethiopic_amete_alem) {:ok, Calendrical.Ethiopic.AmeteAlem} iex> Calendrical.calendar_from_cldr_calendar_type(:dangi) {:ok, Calendrical.Korean} iex> {:error, %Localize.UnknownCalendarError{}} = ...> Calendrical.calendar_from_cldr_calendar_type(:not_a_calendar) # `calendar_from_locale` Return the calendar module for a locale. ### Arguments * `locale` is any locale or locale name validated by `Localize.validate_locale/1`. The default is `Localize.get_locale()` which returns the locale set for the current process. ### Returns * `{:ok, calendar_module}` or * `{:error, exception}` where `exception` is an exception struct ### Examples iex> Calendrical.calendar_from_locale("en-US") {:ok, Calendrical.US} iex> Calendrical.calendar_from_locale("en-GB-u-ca-gregory") {:ok, Calendrical.GB} iex> Calendrical.calendar_from_locale("fa-IR") {:ok, Calendrical.Persian} iex> Calendrical.calendar_from_locale("fa-IR-u-ca-gregory") {:ok, Calendrical.Persian} # `calendar_from_territory` Returns the calendar module preferred for a territory. ### Arguments * `territory` is any valid ISO3166-2 code as an `t:String.t/0` or upcased `atom`. ### Returns * `{:ok, calendar_module}` or * `{:error, exception}` where `exception` is an exception struct ### Examples iex> Calendrical.calendar_from_territory(:US) {:ok, Calendrical.US} iex> {:error, %Localize.UnknownTerritoryError{}} = Calendrical.calendar_from_territory(:YY) ### Notes The overwhelming majority of territories have `:gregorian` as their first preferred calendar and therefore `Calendrical.Gregorian` or a derivation of it will be returned for most territories. Returning any other calendar module would require: 1. That another calendar is preferred over `:gregorian` for a territory 2. That 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](https://hex.pm/packages/ex_cldr_calendars_persian) is installed, the calendar module `Calendrical.Persian` will be returned. If it is not installed, `Calendrical.Gregorian` will be returned as `:gregorian` is the second preference for `:IR`. # `calendar_module?` Returns a boolean indicating if a module is a `Calendrical` module. # `calendar_year` ```elixir @spec calendar_year(date()) :: Calendar.year() | {:error, Exception.t()} ``` Returns the `year` number for a `date` that is the representation used for a calendar. The calendar year may be different the the year in the struct. The struct year is designed for convertability and for date/time arithmetic. The representation in rendered calendar may be different. For example, in the Chinese calendar the cardinal year since epoch is stored in the struct but the calendar year used for representation is the sexigesimal year (a number between 1 and 60). ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * the calendar year as an integer. ### Examples iex> Calendrical.calendar_year(~D[2019-01-01]) 2019 iex> Calendrical.calendar_year(Calendrical.first_day_of_year(2019, Calendrical.NRF)) 2019 iex> Calendrical.calendar_year(Calendrical.last_day_of_year(2019, Calendrical.NRF)) 2019 # `convert` *since 2.4.0* ```elixir @spec convert(Date.t() | Date.Range.t(), Calendar.calendar()) :: {:ok, Date.t() | Date.Range.t()} | {:error, :incompatible_calendars} ``` Converts a date or a date range to another calendar. If the argument is a `t:Calendar.date/0`, `Date.convert/2` is used to do the conversion. If the argument is a `t:Date.Range.t/0` then `Date.convert/2` is applied to the start and end of the range and a new range returned. ### Arguments * `date_or_range` is any `t:Calendar.date/0` or ` t:Date.Range.t/0`. * `calendar` is any valid calendar module. ### Returns * `{:ok, converted_date_or_range}` or * `{:error, :incompatible_calendars}` ### Example # `current` Returns the current date or date range for a date period (year, quarter, month, week or day). ### Arguments * `date_or_date_range` is any `t:Calendar.date/0` or `t:Date.Range.t/0`. * `period` is `:year`, `:quarter`, `:month`, `:week` or `:day`. ### Returns When a `t:Calendar.date/0` is passed, a `t:Calendar.date/0` is returned. When a `t:Date.Range.t/0` is passed a `t:Date.Range.t/0` is returned. ### Examples iex> Calendrical.current(~D[2019-01-01], :day) ~D[2019-01-01] # `cyclic_year` ```elixir @spec cyclic_year(date()) :: Calendar.year() | {:error, Exception.t()} ``` Returns the cycle `year` number for a `date`. A related gregorian year is the gregorian year that is most closely associated with a date that is in another calendar. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * the cyclic year as an integer. ### Examples iex> Calendrical.cyclic_year(~D[2019-01-01]) 2019 iex> Calendrical.cyclic_year(Calendrical.first_day_of_year(2019, Calendrical.NRF)) 2019 iex> Calendrical.cyclic_year(Calendrical.last_day_of_year(2019, Calendrical.NRF)) 2019 # `cyclic_years` Returns the cyclic year data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of cyclic year data. # `date_from_day_of_year` Returns a `t:Calendar.date/0` from a year, day_of_year and a calendar. ### Arguments * `year` is any integer year that is valid in `calendar`. * `day_of_year` is any valid ordinal day of `year`. * `calendar` is any module implementing the `Calendar` and `Calendrical` behaviours. The default is `Calendrical.Gregorian`. ### Returns * a `t:Calendar.date/0` or * `{:error, :invalid_date}` # `date_from_iso_days` ```elixir @spec date_from_iso_days(Calendar.iso_days() | iso_day_number(), calendar()) :: Date.t() | {:error, :incompatible_calendars | :invalid_date} ``` 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 the `Calendar` and `Calendrical` behaviours. ### Returns * a `t:Calendar.date/0` ## Example iex> Calendrical.date_from_iso_days(737425, Calendar.ISO) ~D[2019-01-01] iex> Calendrical.date_from_iso_days(366, Calendar.ISO) ~D[0001-01-01] iex> Calendrical.date_from_iso_days(0, Calendar.ISO) ~D[0000-01-01] # `date_from_list` Returns a `t:Calendar.date/0` from a keyword list and a calendar. ### Arguments * `[year: year, month: month, day: day}` is a keyword list representing a date. * `calendar` is any module implementing the `Calendar` and `Calendrical` behaviours. The default is `Calendrical.Gregorian`. ### Returns * a `t:Calendar.date/0` or * `{:error, :invalid_date}` ### Examples iex> Calendrical.date_from_list([year: 2019, month: 3, day: 25], Calendrical.Gregorian) %Date{calendar: Calendrical.Gregorian, day: 25, month: 3, year: 2019} iex> Calendrical.date_from_list([year: 2019, month: 2, day: 29], Calendrical.Gregorian) {:error, :invalid_date} # `date_from_tuple` Returns a `t:Calendar.date/0` from a date tuple of `{year, month, day}` and a calendar. ### Arguments * `{year, month, day}` is a tuple representing a date. * `calendar` is any module implementing the `Calendar` and `Calendrical` behaviours. The default is `Calendrical.Gregorian`. ### Returns * a `t:Calendar.date/0`. ### Examples iex> Calendrical.date_from_tuple({2019, 3, 25}, Calendrical.Gregorian) %Date{calendar: Calendrical.Gregorian, day: 25, month: 3, year: 2019} iex> Calendrical.date_from_tuple({2019, 2, 29}, Calendrical.Gregorian) {:error, :invalid_date} # `date_to_iso_days` ```elixir @spec 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 any `t:Calendar.date/0`. ### Returns * The integer number of days since the epoch for the given `date`. ## Example iex> Calendrical.date_to_iso_days(~D[2019-01-01]) 737425 iex> Calendrical.date_to_iso_days(~D[0001-01-01]) 366 iex> Calendrical.date_to_iso_days(~D[0000-01-01]) 0 # `date_to_string` ```elixir @spec date_to_string(Date.t()) :: String.t() ``` Formats a date into a string representation. Note that the output is not decorated with the calendar module name. ## Example iex> Calendrical.date_to_string(~D[2019-12-04]) "2019-12-04" iex> Calendrical.date_to_string(~D[2019-23-04 Calendrical.NRF]) "2019-W23-4" # `datetime_from_modified_julian_date` Returns the DateTime (defaulting to UTC timezone) for the given Modified Julian Day. ### Arguments * `mjd` is a number representing days passed since November 17, 1858 (Julian Calendar) ### Returns * a `t:DateTime.t/0` at UTC timezone. ### Examples iex> Calendrical.datetime_from_modified_julian_date(59848) ~U[2022-09-26 00:00:00.000Z] iex> Calendrical.datetime_from_modified_julian_date(59848.75) ~U[2022-09-26 18:00:00.000Z] # `day_of_era` ```elixir @spec day_of_era(date()) :: {Calendar.day(), Calendar.era()} | {:error, Exception.t()} ``` Returns the `{day_of_era, era}` for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * a the days since the start of the era and the era of the year as a tuple. ### Examples iex> Calendrical.day_of_era ~D[2019-01-01] {737060, 1} iex> Calendrical.day_of_era(Calendrical.first_day_of_year(2019, Calendrical.NRF)) {737093, 1} iex> Calendrical.day_of_era(Calendrical.last_day_of_year(2019, Calendrical.NRF)) {737456, 1} # `day_of_week` # `day_of_week` # `day_of_year` ```elixir @spec day_of_year(date()) :: Calendar.day() | {:error, Exception.t()} ``` Returns the `day` of the year for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * a the day of the year as an integer ### Examples iex> Calendrical.day_of_year(~D[2019-01-01]) 1 iex> Calendrical.day_of_year(~D[2016-12-31]) 366 iex> Calendrical.day_of_year(~D[2019-12-31]) 365 iex> Calendrical.day_of_year(~D[2019-52-07 Calendrical.NRF]) 365 iex> Calendrical.day_of_year(~D[2012-53-07 Calendrical.NRF]) 372 # `day_periods` Returns the day period data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of day period data. # `days` Returns the day name data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of day name data. # `days_in_month` # `default_calendar` Returns the default calendar. # `do_cardinal_day_of_week` # `eras` Returns the era data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of era data. # `extended_year` ```elixir @spec extended_year(date()) :: Calendar.year() | {:error, Exception.t()} ``` Returns the extended `year` number for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * the extended calendar year as an integer. ### Examples iex> Calendrical.extended_year(~D[2019-01-01]) 2019 iex> Calendrical.extended_year(Calendrical.first_day_of_year(2019, Calendrical.NRF)) 2019 iex> Calendrical.extended_year(Calendrical.last_day_of_year(2019, Calendrical.NRF)) 2019 # `first_day_for_locale` Returns the first day of a week for a given locale where `1` means `Monday` and `7` means `Sunday`. Note that the first day of the first week is commonly not aligned with the first day of the year. # `first_day_for_locale` # `first_day_for_territory` Returns the first day of the week for a given territory. ### Arguments * `territory` is any valid ISO3166-2 code. ### Returns * The first day of the week for this territory. Here `1` means `Monday` and `7` means `Sunday`. # `first_day_of_year` ```elixir @spec first_day_of_year(date :: date()) :: Date.t() | {:error, :invalid_date} ``` Returns the first date of a `year` for a `t:Calendar.date/0`. ### Arguments * `date` is any `t:Calendar.date/0`. ### Returns * a `t:Calendar.date/0` or * `{:error, :invalid_date}` ### Examples iex> Calendrical.first_day_of_year(~D[2019-12-01]) ~D[2019-01-01] # `first_day_of_year` ```elixir @spec first_day_of_year(year :: year(), calendar :: calendar()) :: Date.t() | {:error, :invalid_date} ``` Returns the first date of a `year` in a `calendar`. ### Arguments * `year` is any year. * `calendar` is any module that implements the `Calendar` and `Calendrical` behaviours. ### Returns * a `t:Calendar.date/0` or * `{:error, :invalid_date}` ### Examples iex> Calendrical.first_day_of_year(2019, Calendrical.Gregorian) %Date{calendar: Calendrical.Gregorian, day: 1, month: 1, year: 2019} iex> Calendrical.first_day_of_year(2019, Calendrical.NRF) %Date{calendar: Calendrical.NRF, day: 1, month: 1, year: 2019} # `first_gregorian_day_of_year` Returns the gregorian date of the first day of of a `year` for a `calendar`. ### Arguments * `year` is any integer year number. * `calendar` is any module that implements the `Calendar` and `Calendrical` behaviours or `Calendar.ISO` ### Examples iex> Calendrical.first_gregorian_day_of_year(2019, Calendrical.Gregorian) %Date{calendar: Calendrical.Gregorian, day: 1, month: 1, year: 2019} iex> Calendrical.first_gregorian_day_of_year(2019, Calendrical.NRF) %Date{calendar: Calendrical.Gregorian, day: 3, month: 2, year: 2019} iex> Calendrical.first_gregorian_day_of_year(~D[2019-12-01]) ~D[2019-01-01] # `first_gregorian_day_of_year` ```elixir @spec first_gregorian_day_of_year(year() | date(), calendar()) :: Date.t() | {:error, :invalid_date} ``` # `friday` ```elixir @spec friday() :: 5 ``` Returns the cardinal day number representing Friday. # `inspect` ```elixir @spec 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: &Calendrical.inspect/2]) :ok # `interval` ```elixir @spec 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 any `t:Calendar.date/0` that is the start of the sequence. * `date_to_or_count` is upper bound of the sequence as a `t:Calendar.date/0` or the number of dates in the sequence to be generated. * `precision` 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> Calendrical.interval(d, 3, :months) [~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31]] iex> Calendrical.interval(d, d2, :months) [~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31], ~D[2019-04-30], ~D[2019-05-31]] # `interval_stream` ```elixir @spec interval_stream( date_from :: Date.t(), date_to_or_count :: Date.t() | non_neg_integer(), precision() ) :: fun() ``` Returns an a `Stream` function than can be lazily enumerated. This function has the same arguments and provides the same functionality as `interval/3` except that it is lazily evaluated. ### Arguments * `date_from` is a any `t:Calendar.date/0` that is the start of the sequence. * `date_to_or_count` is upper bound of the sequence as a `t:Calendar.date/0` or the number of dates in the sequence to be generated. * `precision` 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> Calendrical.interval_stream(d, 3, :months) |> Enum.to_list [~D[2019-01-31], ~D[2019-02-28], ~D[2019-03-31]] iex> Calendrical.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]] # `iso_day_of_week` ```elixir @spec iso_day_of_week(date()) :: Calendar.day_of_week() ``` Returns the ISO day of week for a `date` where `1` means `Monday` and `7` means `Sunday`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * An integer ISO day of week in the range `1..7` where `1` is `Monday` and `7` is `Sunday`. ### Examples iex> {:ok, us_calendar} = Calendrical.calendar_from_locale("en") iex> {:ok, us_date} = Date.new(2025, 1, 1, us_calendar) iex> Calendrical.iso_day_of_week(us_date) 3 # `iso_days_to_day_of_week` ```elixir @spec 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. See `Calendrical.date_to_iso_days/1`. ### Returns * An integer representing a day of the week where Monday is represented by `1` and Sunday is represented by `7`. ### Examples iex> days = Calendrical.date_to_iso_days(~D[2019-01-01]) iex> Calendrical.iso_days_to_day_of_week(days) == Calendrical.tuesday() true # `iso_week_of_year` ```elixir @spec iso_week_of_year(date()) :: {Calendar.year(), week()} | {:error, Exception.t()} ``` Returns the `ISO week` number for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### 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> Calendrical.iso_week_of_year(~D[2019-01-01]) {2019, 1} iex> Calendrical.iso_week_of_year(~D[2019-02-01]) {2019, 5} iex> Calendrical.iso_week_of_year(~D[2019-52-01 Calendrical.NRF]) {2020, 4} iex> Calendrical.iso_week_of_year(~D[2019-26-01 Calendrical.NRF]) {2019, 30} iex> Calendrical.iso_week_of_year(~D[2019-12-01 Calendrical.Julian]) {:error, :not_defined} # `last_day_of_year` ```elixir @spec last_day_of_year(date :: date()) :: Date.t() ``` Returns the last date of a `year` for a `t:Calendar.date/0`. ### Arguments * `date` is any `t:Calendar.date/0`. ### Returns * a `t:Calendar.date/0` or * `{:error, :invalid_date}` ### Examples iex> Calendrical.last_day_of_year(~D[2019-01-01]) ~D[2019-12-31] # `last_day_of_year` ```elixir @spec last_day_of_year(year :: year(), calendar :: calendar()) :: Date.t() ``` Returns the last date of a `year` for a `calendar`. ### Arguments * `year` is any year. * `calendar` is any module that implements the `Calendar` and `Calendrical` behaviours ### Returns * a `t:Calendar.date/0` or * `{:error, :invalid_date}` ### Examples iex> Calendrical.last_day_of_year(2019, Calendrical.Gregorian) %Date{calendar: Calendrical.Gregorian, day: 31, month: 12, year: 2019} iex> Calendrical.last_day_of_year(2019, Calendrical.NRF) %Date{calendar: Calendrical.NRF, day: 7, month: 52, year: 2019} # `last_gregorian_day_of_year` Returns the gregorian date of the first day of a `year` for a `calendar`. ### Arguments * `year` is any integer year number or a `t:date/0`. * `calendar` is any module that implements the `Calendar` and `Calendrical` behaviours or `Calendar.ISO`. ### Examples iex> Calendrical.last_gregorian_day_of_year(2019, Calendrical.Gregorian) %Date{calendar: Calendrical.Gregorian, day: 31, month: 12, year: 2019} iex> Calendrical.last_gregorian_day_of_year(2019, Calendrical.NRF) %Date{calendar: Calendrical.Gregorian, day: 1, month: 2, year: 2020} iex> Calendrical.last_gregorian_day_of_year(~D[2019-12-01]) ~D[2019-12-31] # `last_gregorian_day_of_year` ```elixir @spec last_gregorian_day_of_year(date() | year(), calendar()) :: Date.t() | {:error, :invalid_date} ``` # `localize` *since 1.19.0* ```elixir @spec localize(any_date_time()) :: {:ok, any_date_time()} | {:error, :incompatible_calendars} | {:error, Exception.t()} ``` Localize a date by converting it to calendar introspected from the provided or default locale. ### Arguments * `date` is any `t:Calendar.date/0`. * `options` is a `t:Keyword.t/0` list of options. The default is `[]`. ### Options * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. ### Returns * `{:ok, date}` where `date` is converted into the calendar associated with the current or provided locale. ### Examples iex> Calendrical.localize(~D[2022-06-09], locale: "fr") {:ok, %Date{year: 2022, month: 6, day: 9, calendar: Calendrical.FR}} # `localize` *since 1.19.0* ```elixir @spec localize(any_date_time(), Keyword.t() | atom()) :: {:ok, any_date_time()} | {:error, :incompatible_calendars} | {:error, Exception.t()} ``` # `localize` ```elixir @spec localize(any_date_time(), atom(), Keyword.t()) :: String.t() | {:error, :incompatible_calendars} | {:error, Exception.t()} @spec localize(datetime :: any_date_time(), part :: part(), options :: Keyword.t()) :: String.t() | {:error, Exception.t()} ``` Returns a localized string for a part of a `t:Calendar.date/0`. ### Arguments * `date` is any `t:Calendar.date/0`. * `part` is one of `:era`, `:quarter`, `:month`, `:day_of_week` or `:days_of_week`. * `options` is a `t:Keyword.t/0` list of options. ### Options * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `:format` is one of `:wide`, `:abbreviated` or `:narrow`. The default is `:abbreviated`. * `:era` will, if set to `:variant` localize the era using the variant data. In the `:en` locale, this will produce `CE` and `BCE` rather than the default `AD` and `BC`. * `:am_pm` will, if set to `:variant` localize the "AM"/"PM" time period indicator with the variant data. In the `:en` locale, this will produce `am` and `pm` rather than the default `AM` and `PM`. ### Returns * A string representing the localized date part, or * A list of strings representing the days of the week for when `part` is `:days_of_week`. The days are in week order for the given date's calendar, or * `{error, {exception_module, message}}` if an error is detected ### Examples iex> Calendrical.localize(~D[2019-01-01], :era) "AD" iex> Calendrical.localize(~D[2019-01-01], :era, era: :variant) "CE" iex> Calendrical.localize(~D[2019-01-01], :day_of_week) "Tue" iex> Calendrical.localize(~D[0001-01-01], :day_of_week) "Mon" iex> Calendrical.localize(~D[2019-01-01], :days_of_week) [{1, "Mon"}, {2, "Tue"}, {3, "Wed"}, {4, "Thu"}, {5, "Fri"}, {6, "Sat"}, {7, "Sun"}] iex> Calendrical.localize(~D[2019-06-01], :era) "AD" iex> Calendrical.localize(~D[2019-06-01], :quarter) "Q2" iex> Calendrical.localize(~D[2019-06-01], :month) "Jun" iex> Calendrical.localize(~D[2019-06-01], :day_of_week) "Sat" iex> Calendrical.localize(~D[2019-06-01], :day_of_week, format: :wide) "Saturday" iex> Calendrical.localize(~D[2019-06-01], :day_of_week, format: :narrow) "S" iex> Calendrical.localize(~D[2019-06-01], :day_of_week, locale: "ar") "السبت" # `min_days_for_locale` Returns the minimum days in the first week of a year for a given locale. # `min_days_for_locale` # `min_days_for_territory` # `modified_julian_day` Returns the Modified Julian Day of a `t:Calendar.date/0`. ### Arguments * `date_or_datetime` is any `t:Calendar.date/0` or a `t:DateTime.t/0`. If a `t:DateTime.t/0` is given, the result will be given in the current timezone. ### Returns * an 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> Calendrical.modified_julian_day(~D[2019-01-01]) 58484.0 iex> Calendrical.modified_julian_day(~U[2019-01-01 12:00:00Z]) 58484.5 iex> Calendrical.modified_julian_day(~U[2022-09-26 18:00:00.000Z]) 59848.75 # If the given DateTime is not UTC, the result is given in # the local timezone. This example requires a time zone database # such as `tz` or `tzdata` to be configured. # # dt = DateTime.shift_zone!(~U[2019-01-01 14:00:00Z], "America/Sao_Paulo") # #=> #DateTime<2019-01-01 12:00:00-02:00 -02 America/Sao_Paulo> # Calendrical.modified_julian_day(dt) # #=> 58484.5 # `monday` ```elixir @spec monday() :: 1 ``` Returns the cardinal day number representing Monday # `month_names` *since 2.3.0* ```elixir @spec month_names(calendar :: calendar(), options :: Keyword.t()) :: [{pos_integer(), String.t()}] | {:error, Exception.t()} ``` Returns a sorted list of tuples containing ordinal months and month names for a give calendar. ### Arguments * `calendar` is any calendar module. * `options` is a keyword list of options. ### Options * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `:type` is one of `:stand_alone` or `:format`. The default is `:format`. * `:format` is one of `:abbreviated`, `Lwide` or `:narrow`. The default is `:abbreviated`. ### Returns * A sorted list of tuples of the format `{ordinal month number, month name}`. ### Examples iex> Calendrical.month_names(Calendar.ISO, format: :wide) %{ 1 => "January", 2 => "February", 3 => "March", 4 => "April", 5 => "May", 6 => "June", 7 => "July", 8 => "August", 9 => "September", 10 => "October", 11 => "November", 12 => "December" } iex> Calendrical.month_names(Calendar.ISO, locale: :de) %{ 1 => "Jan.", 2 => "Feb.", 3 => "März", 4 => "Apr.", 5 => "Mai", 6 => "Juni", 7 => "Juli", 8 => "Aug.", 9 => "Sept.", 10 => "Okt.", 11 => "Nov.", 12 => "Dez." } iex> Calendrical.month_names(Calendrical.Gregorian, locale: :fr, format: :narrow) %{ 1 => "J", 2 => "F", 3 => "M", 4 => "A", 5 => "M", 6 => "J", 7 => "J", 8 => "A", 9 => "S", 10 => "O", 11 => "N", 12 => "D" } # `month_of_year` ```elixir @spec month_of_year(date()) :: Calendar.month() | {Calendar.month(), leap_month :: :leap} | {:error, Exception.t()} ``` Returns the `month` number for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * the month of the year as an integer ### Examples iex> Calendrical.month_of_year(~D[2019-01-01]) 1 iex> Calendrical.month_of_year(~D[2019-12-01]) 12 iex> Calendrical.month_of_year(~D[2019-52-01 Calendrical.NRF]) 12 iex> Calendrical.month_of_year(~D[2019-26-01 Calendrical.NRF]) 6 # `month_patterns` Returns the month pattern data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of month pattern data, or `nil` if no patterns exist. # `months` Returns the month name data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of month name data. # `months_in_year` # `new` ```elixir @spec new(module(), calendar_type(), Keyword.t()) :: {:ok, calendar()} | {:module_already_exists, module()} | {:error, String.t()} ``` Creates a new proleptic gregrian 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 an atom representing the module name of the created calendar. * `calendar_type` is an atom of either `:month` or `:week` indicating which type of calendar is to be created. * `config` is a Keyword list defining the configuration of the calendar. ### Returns * `{:ok, module}` where `module` is the new calendar module that conforms to the `Calendar` and `Calendrical` 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. * `: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 parameter `day_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 range `1..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 is `1`. * `:month_of_year` determines the `Calendrical.Gregorian` month of year in which this calendar begins or ends. The default is `1`. * `:year` is used to determine which calendar Gregogian year is applicable for a given calendar date. The valid options are `:first`, `:last` and `:majority`. The default is `:majority`. * `:min_days_in_first_week` is used to determine how many days of the `Calendrical.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 is `4` which is consistent with the [ISO Week calendar](https://en.wikipedia.org/wiki/ISO_week_date) ### Examples Each calendar has a function `__config__/0` generated within it and therefore the configuration 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](https://en.wikipedia.org/wiki/ISO_week_date) calendar in full: ``` defmodule ISOWeek do use Calendrical.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 Calendrical.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, 4, 5], # The weeks are laid out as *months* in a `[4,4,5]` pattern year: :majority, # Any given year is that in which the majority of Calendrical.Gregorian months fall locale: nil # No `locale` is used to aid configuration end ``` This can be generated at runtime by: iex> {_, MyISOWeek} = Calendrical.new MyISOWeek, :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, 4, 5], ...> year: :majority Note that `Calendrical.ISOWeek` is included as part of this library. # `next` Returns the next date or date range for a date period (year, quarter, month, week or day). ### Arguments * `date_or_date_range` is any `t:Calendar.date/0` or `t:Date.Range.t/0`. * `period` is `:year`, `:quarter`, `:month`, ` :week` or `:day`. ### Returns When a `t:Calendar.date/0` is passed, a `t:Calendar.date/0` is returned. When a `t:Date.Range.t/0` is passed a `t:Date.Range.t/0` is returned. ### Examples iex> Calendrical.next(~D[2019-01-01], :day) ~D[2019-01-02] iex> Calendrical.next(~D[2019-01-01], :month) ~D[2019-02-01] iex> Calendrical.next(~D[2019-01-01], :quarter) ~D[2019-04-01] iex> Calendrical.next(~D[2019-01-01], :year) ~D[2020-01-01] # `previous` Returns the previous date or date range for a date period (year, quarter, month, week or day). ### Arguments * `date_or_date_range` is any `t:Calendar.date/0` or `t:Date.Range.t/0`. * `period` is `:year`, `:quarter`, `:month`, `:week` or `:day`. * `options` is a `t:Keyword.t/0` list of options. ### Returns When a `t:Calendar.date/0` is passed, a `t:Calendar.date/0` is returned. When a `t:Date.Range.t/0` is passed a `t:Date.Range.t/0` is returned. ### Examples iex> Calendrical.previous(~D[2019-01-01], :day) ~D[2018-12-31] iex> Calendrical.previous(~D[2019-01-01], :quarter) ~D[2018-10-01] iex> Calendrical.previous(~D[2019-01-01], :month) ~D[2018-12-01] iex> Calendrical.previous(~D[2019-01-01], :year) ~D[2018-01-01] # `quarter_of_year` ```elixir @spec quarter_of_year(date()) :: quarter() | {:error, Exception.t()} ``` Returns the `quarter` number for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * a the quarter of the year as an integer ### Examples iex> Calendrical.quarter_of_year(~D[2019-01-01]) 1 iex> Calendrical.quarter_of_year(Calendrical.first_day_of_year(2019, Calendrical.NRF)) 1 iex> Calendrical.quarter_of_year(Calendrical.last_day_of_year(2019, Calendrical.NRF)) 4 # `quarters` Returns the quarter name data for a locale and calendar type. ### Arguments * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `calendar` is a calendar type atom. The default is `:gregorian`. ### Returns * A map of quarter name data. # `related_gregorian_year` ```elixir @spec related_gregorian_year(date()) :: Calendar.year() | {:error, Exception.t()} ``` Returns the related gregorian `year` number for a `date`. A related gregorian year is the gregorian year that is most closely associated with a date that is in another calendar. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * the related gregorian year as an integer. ### Examples iex> Calendrical.related_gregorian_year ~D[2019-01-01] 2019 iex> Calendrical.related_gregorian_year(Calendrical.first_day_of_year(2019, Calendrical.NRF)) 2019 iex> Calendrical.related_gregorian_year(Calendrical.last_day_of_year(2019, Calendrical.NRF)) 2019 # `saturday` ```elixir @spec saturday() :: 6 ``` Returns the cardinal day number representing Saturday. # `strftime` Formats the given date, time, or datetime into a string. This function is a thin wrapper around `Calendar.strftime/3` intended to ease formatting for localized calendars. Localized strings will be automatically injected as options to `Calendar.strftime/3`. See `Calendar.strftime/3` for details of formatting strings and other options. Examples: iex> Calendrical.strftime(~D[2025-01-26 Calendrical.IL], "%a", locale: :he) "יום ב׳" # `strftime_options!` Returns a keyword list of options than can be applied to `Calendar.strftime/3` or `Calendrical.strftime/3`. `strftime_options!` returns a keyword list than can be used as options to return localised names for days, months and am/pm. ## Arguments * `options` is a set of keyword options. The default is `[]`. ## Options * `:locale` is a locale identifier atom, string, or a `t:Localize.LanguageTag.t/0`. The default is `Localize.get_locale/0`. * `:calendar` is the name of any known calendar. The default is `Calendrical.Gregorian`. ## Example iex: Calendrical.strftime_options!() [ am_pm_names: #Function<0.32021692/1 in Calendrical.strftime_options/2>, month_names: #Function<1.32021692/1 in Calendrical.strftime_options/2>, abbreviated_month_names: #Function<2.32021692/1 in Calendrical.strftime_options/2>, day_of_week_names: #Function<3.32021692/1 in Calendrical.strftime_options/2>, abbreviated_day_of_week_names: #Function<4.32021692/1 in Calendrical.strftime_options/2> ] ## Typical usage iex> Calendar.strftime(~D[2025-01-26 Calendrical.IL], "%a", ...> Calendrical.strftime_options!(calendar: Calendrical.IL, locale: "en")) "Mon" # `sunday` ```elixir @spec sunday() :: 7 ``` Returns the cardinal day number representing Sunday. # `supported_cldr_calendar_types` ```elixir @spec supported_cldr_calendar_types() :: [atom(), ...] ``` Returns the list of CLDR calendar types supported by Calendrical. The returned types are the names recognised by `Localize.validate_calendar/1` and are the valid inputs to `calendar_from_cldr_calendar_type/1`. ### Returns * A list of CLDR calendar type atoms. ### Examples iex> calendars = Calendrical.supported_cldr_calendar_types() iex> :gregorian in calendars and :persian in calendars and :hebrew in calendars true # `thursday` ```elixir @spec thursday() :: 4 ``` Returns the cardinal day number representing Thursday. # `tuesday` ```elixir @spec tuesday() :: 2 ``` Returns the cardinal day number representing Tuesday. # `validate_calendar` Validates if the argument is a Calendrical calendar module. If the calendar is `Calendar.ISO` then the validated calendar is returned as `Calendrical.Gregorian`. ### Arguments * `calendar_module` is a module that implements the `Calendrical` behaviour. ### Returns * `{:ok, calendar_module}` or * `{:error, exception}` where `exception` is an exception struct ### Examples iex> Calendrical.validate_calendar(Calendrical.Gregorian) {:ok, Calendrical.Gregorian} iex> Calendrical.validate_calendar(Calendar.ISO) {:ok, Calendrical.Gregorian} iex> {:error, %Calendrical.InvalidCalendarModuleError{module: :not_a_calendar}} = ...> Calendrical.validate_calendar(:not_a_calendar) # `wednesday` ```elixir @spec wednesday() :: 3 ``` Returns the cardinal day number representing Wednesday. # `week_of_month` ```elixir @spec week_of_month(date()) :: {Calendar.month(), week()} | {:error, Exception.t()} ``` 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 any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * a tuple of the form `{month, week}` or * `{:error, :not_defined}` if the calendar does not support the concept of weeks. ### Examples iex> Calendrical.week_of_month(~D[2019-01-01]) {1, 1} iex> Calendrical.week_of_month(~D[2018-12-31]) {1, 1} iex> Calendrical.week_of_month(~D[2019-01-01 Calendrical.BasicWeek]) {1, 1} iex> Calendrical.week_of_month(~D[2018-12-31 Calendrical.BasicWeek]) {12, 5} iex> Calendrical.week_of_month(~D[2018-12-31 Calendrical.Julian]) {:error, :not_defined} # `week_of_year` ```elixir @spec week_of_year(date()) :: {Calendar.year(), week()} | {:error, Exception.t()} ``` Returns the `{year, week_number}` for a `date`. ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### 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> Calendrical.week_of_year(~D[2019-01-01]) {2019, 1} iex> Calendrical.week_of_year(~D[2019-12-01]) {2019, 48} iex> Calendrical.week_of_year(~D[2019-52-01 Calendrical.NRF]) {2019, 52} iex> Calendrical.week_of_year(~D[2019-26-01 Calendrical.NRF]) {2019, 26} iex> Calendrical.week_of_year(~D[2019-12-01 Calendrical.Julian]) {:error, :not_defined} # `weekday?` ```elixir @spec weekday?(date(), Keyword.t()) :: boolean() | {:error, Exception.t()} ``` Returns whether a given date is a weekday. Weekdays are locale-specific and depend on the policies of a given territory (region, country). ### Arguments * `date` is any `t:Calendar.date/0`. * `options` is a `t:Keyword.t/0` list of options. ### Options * `:locale` is any locale or locale name validated by `Localize.validate_locale/1`. The default is `Localize.get_locale/0` which returns the locale set for the current process. * `:territory` is any valid ISO-3166-2 territory that is validated by `Localize.validate_territory/1`. ### 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` option. * The territory defined as part of the `:locale` option. * The territory defined as part of the current processes default locale. ### Examples # The default locale is `en-001` for which # the territory is `001` (the world). The weekdays # for `001` are Monday to Friday iex> Calendrical.weekday?(~D[2019-03-23], locale: :en) false iex> Calendrical.weekday?(~D[2019-03-23], territory: "IS") false # Saturday is a weekday in India iex> Calendrical.weekday?(~D[2019-03-23], locale: :"en-IN") true # Friday is not a weekday in Saudi Arabia iex> Calendrical.weekday?(~D[2019-03-22], locale: :"ar-SA") false # Friday is not a weekday in Israel iex> Calendrical.weekday?(~D[2019-03-22], locale: :he) false iex> Calendrical.weekday?(~D[2019-03-22 Calendrical.IL], locale: :he) false # `weekdays` 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. Here `1` means `Monday` and `7` means `Sunday`. ### Notes The list of days may not be monotonic. See the example for Saudi Arabia below. ### Examples iex> Calendrical.weekdays("US") [1, 2, 3, 4, 5] iex> Calendrical.weekdays("IN") [1, 2, 3, 4, 5, 6] iex> Calendrical.weekdays("SA") [1, 2, 3, 4, 7] iex> {:error, %Localize.UnknownTerritoryError{}} = Calendrical.weekdays("yy") # `weekend` Returns a list of the days of the week that are considered a weekend for a given territory (region, country). ### Arguments * `territory` is any valid ISO3166-2 code. ### Returns * A list of integers representing the days of the week that are weekend days. Here `1` means `Monday` and `7` means `Sunday`. ### Examples iex> Calendrical.weekend("US") [6, 7] iex> Calendrical.weekend("IN") [7] iex> Calendrical.weekend("SA") [5, 6] iex> {:error, %Localize.UnknownTerritoryError{}} = Calendrical.weekend("yy") # `weekend?` ```elixir @spec weekend?(date(), Keyword.t()) :: boolean() | {:error, Exception.t()} ``` 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 any `t:Calendar.date/0`. * `options` is a `t:Keyword.t/0` list of options. ### Options * `:locale` is any locale or locale name validated by `Localize.validate_locale/1`. The default is `Localize.get_locale/0` which returns the locale set for the current process. * `:territory` is any valid ISO-3166-2 territory that is validated by `Localize.validate_territory/1`. ### 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` option. * The territory defined as part of the `:locale` option. * The territory defined as part of the current processes default locale. ### Examples # The default locale is `en-001` for which # the territory is `001` (the world). The weekend # for `001` is Saturday and Sunday iex> Calendrical.weekend? ~D[2019-03-23] true iex> Calendrical.weekend?(~D[2019-03-23], locale: :en) true iex> Calendrical.weekend?(~D[2019-03-23], territory: "IS") true # In India the official weekend is only Sunday iex> Calendrical.weekend?(~D[2019-03-23], locale: "en-IN") false # In Israel the weekend starts on Friday iex> Calendrical.weekend?(~D[2019-03-22], locale: :he) true iex> Calendrical.weekend?(~D[2019-03-22 Calendrical.IL], locale: :he) true # As it also does in Saudia Arabia iex> Calendrical.weekend?(~D[2019-03-22], locale: :"ar-SA") true # Sunday is not a weekend day in Saudi Arabia iex> Calendrical.weekend?(~D[2019-03-24], locale: :"ar-SA") false # `weeks_in_year` ```elixir @spec weeks_in_year(date()) :: {week(), Calendar.day_of_week()} | {:error, Exception.t()} ``` Returns the number of weeks in a year. ### Arguments * `date` is any `t:Calendar.date/0` or an integer year or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * `{weeks_in_year, days_in_last_week}` ### Examples # For the default Calendar.ISO calendar the number of # weeks in a year is either 52 or 53 with each week # being 7 days. The first week may start in the Gregorian # year prior and end in the following Gregorian year. iex> Calendrical.weeks_in_year(~D[2022-01-01]) {52, 7} iex> Calendrical.weeks_in_year(~D[2023-01-01]) {53, 7} # For week calculations, the Calendrical.ISO and Calendrical.ISOWeek # have the same definition. iex> Calendrical.weeks_in_year(2023, Calendrical.ISO) {52, 7} iex> Calendrical.weeks_in_year(2020, Calendrical.ISOWeek) {53, 7} iex> Calendrical.weeks_in_year(~D[2026-W01-1 Calendrical.ISOWeek]) {53, 7} # For calendars that are configured to have the first week # start on the first day of the year there will be a final # week 53 with either 1 or 2 days. iex> Calendrical.SequentialWeeks.weeks_in_year(2023) {53, 1} iex> Calendrical.SequentialWeeks.weeks_in_year(2020) {53, 2} # `weeks_in_year` ```elixir @spec weeks_in_year(year(), calendar()) :: {week(), Calendar.day_of_week()} | {:error, Exception.t()} ``` # `weeks_to_days` ```elixir @spec weeks_to_days(integer()) :: integer() ``` Returns the number of days in `n` weeks ## Example iex> Calendrical.weeks_to_days(2) 14 # `year_of_era` ```elixir @spec year_of_era(date()) :: {Calendar.day(), Calendar.era()} | {:error, Exception.t()} ``` Returns the `{year_of_era, era}` for a `date`. *This function differs slightly from `Date.year_of_era/1`. See the notes below* ### Arguments * `date` is any `t:Calendar.date/0` or a map with one or more of the fields `:year`, `:month`, `:day` and optionally `:calendar`. ### Returns * a the year since the start of the era and the era of the year as a tuple. ### Notes 1. Unlike `Date.year_of_era/1`, this function supports eras that change part way through the calendar year. This is common in the Japanese calendar where the eras change when a new emperor is ordained which can happen at any time of year. Therefore this function is consistent with `Date.year_of_era/1` for the Gregorian and related calendars, but returns a different (and more accurate) result for the Japanese calendar. 2. This is also true for fiscal year calendars that start on a day other than January 1st. The year of era will depend on whether the calendar was configured with `year: :beginning`, `year: :ending` or `year: :majority`. ### Examples iex> Calendrical.year_of_era(~D[2019-01-01]) {2019, 1} iex> Calendrical.year_of_era(Calendrical.first_day_of_year(2019, Calendrical.NRF)) {2019, 1} iex> Calendrical.year_of_era(Calendrical.last_day_of_year(2019, Calendrical.NRF)) {2019, 1} --- *Consult [api-reference.md](api-reference.md) for complete listing*