# `Calendrical.Coptic` Implementation of the Coptic calendar. The Coptic calendar is a 13-month calendar derived from the ancient Egyptian calendar, currently used by the Coptic Orthodox Church of Alexandria. The first twelve months each have 30 days; the thirteenth month (the *epagomenal* month Pi Kogi Enavot) has 5 days, or 6 in a leap year. The epoch is the start of the Era of Martyrs (anno martyrum), 29 August 284 CE in the Julian calendar. # `day` ```elixir @type day() :: 1..30 ``` # `month` ```elixir @type month() :: 1..13 ``` # `year` ```elixir @type year() :: -9999..-1 | 1..9999 ``` # `calendar_base` Identifies whether this calendar is month or week based. # `calendar_year` ```elixir @spec calendar_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendar.year() ``` Returns the calendar year as displayed on rendered calendars. # `cldr_calendar_type` Defines the CLDR calendar type for this calendar. This type is used in support of `Calendrical. localize/3`. # `cyclic_year` ```elixir @spec cyclic_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendar.year() ``` Returns the cyclic year as displayed on rendered calendars. # `date_from_iso_days` Returns a Coptic `{year, month, day}` for the given ISO day number. # `date_to_iso_days` Returns the number of ISO days for the given Coptic `year`, `month`, and `day`. # `day_of_era` ```elixir @spec day_of_era(Calendar.year(), Calendar.month(), Calendar.day()) :: {day :: Calendar.day(), era :: Calendar.era()} ``` Calculates the day and era from the given `year`, `month`, and `day`. # `day_of_week` ```elixir @spec day_of_week( Calendar.year(), Calendar.month(), Calendar.day(), :default | atom() ) :: {Calendar.day_of_week(), first_day_of_week :: non_neg_integer(), last_day_of_week :: non_neg_integer()} ``` Returns the day of the week for the given `year`, `month`, and `day`. Coptic weeks begin on Saturday, so the returned tuple has `first_day_of_week = 6` and `last_day_of_week = 5`. # `day_of_year` ```elixir @spec day_of_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendar.day() ``` Calculates the day of the year from the given `year`, `month`, and `day`. # `days_in_month` ```elixir @spec days_in_month(Calendar.month()) :: Calendar.month() | {:ambiguous, Range.t() | [pos_integer()]} | {:error, :undefined} ``` Returns how many days there are in the given month. Must be implemented in derived calendars because we cannot know what the calendar format is. # `days_in_month` ```elixir @spec days_in_month(Calendar.year(), Calendar.month()) :: Calendar.month() @spec days_in_month(year(), month()) :: 5..30 ``` Returns the number of days in the given `year` and `month`. Months 1-12 always have 30 days; month 13 has 5 days, or 6 in a leap year. # `days_in_week` Returns the number days in a a week. # `days_in_year` Returns the number of days in the given `year`. # `epoch` # `epoch_day_of_week` # `extended_year` ```elixir @spec extended_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendar.year() ``` Returns the extended year as displayed on rendered calendars. # `first_day_of_week` # `iso_week_of_year` ```elixir @spec iso_week_of_year(Calendar.year(), Calendar.month(), Calendar.day()) :: {:error, :not_defined} ``` Calculates the ISO week of the year from the given `year`, `month`, and `day`. By default this function always returns `{:error, :not_defined}`. # `last_day_of_week` # `leap_year?` Returns whether the given `year` is a Coptic leap year. A Coptic year is a leap year when it is one less than a multiple of four. # `month` Returns a `t:Date.Range.t/0` representing a given month of a year. # `month_of_year` ```elixir @spec month_of_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendar.month() | {Calendar.month(), Calendrical.leap_month?()} ``` Returns the month of the year from the given `year`, `month`, and `day`. # `months_in_leap_year` Returns the number of months in a leap year. # `months_in_ordinary_year` Returns the number of months in a normal year. # `months_in_year` Returns the number of months in a given `year`. # `naive_datetime_from_iso_days` ```elixir @spec naive_datetime_from_iso_days(Calendar.iso_days()) :: {Calendar.year(), Calendar.month(), Calendar.day(), Calendar.hour(), Calendar.minute(), Calendar.second(), Calendar.microsecond()} ``` Converts the `t:Calendar.iso_days` format to the datetime format specified by this calendar. # `naive_datetime_to_iso_days` ```elixir @spec naive_datetime_to_iso_days( Calendar.year(), Calendar.month(), Calendar.day(), Calendar.hour(), Calendar.minute(), Calendar.second(), Calendar.microsecond() ) :: Calendar.iso_days() ``` Returns the `t:Calendar.iso_days` format of the specified date. # `periods_in_year` Returns the number of periods in a given `year`. A period corresponds to a month in month-based calendars and a week in week-based calendars. # `plus` Adds an `increment` number of `date_part`s to a `year-month-day`. `date_part` can be `:months` only. # `quarter` Returns a `t:Date.Range.t/0` representing a given quarter of a year. # `quarter_of_year` ```elixir @spec quarter_of_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendrical.quarter() ``` The Coptic calendar does not define quarters because the year has 13 months. # `related_gregorian_year` ```elixir @spec related_gregorian_year(Calendar.year(), Calendar.month(), Calendar.day()) :: Calendar.year() ``` Calculates the related Gregorian year for a Coptic date by converting via ISO days. # `valid_date?` Determines if the date given is valid according to this calendar. # `week` Returns a `t:Date.Range.t/0` representing a given week of a year. # `week_of_month` ```elixir @spec week_of_month(Calendar.year(), Calendar.month(), Calendar.day()) :: {pos_integer(), pos_integer()} | {:error, :not_defined} ``` Calculates the week of the year from the given `year`, `month`, and `day`. By default this function always returns `{:error, :not_defined}`. # `week_of_year` ```elixir @spec week_of_year(Calendar.year(), Calendar.month(), Calendar.day()) :: {:error, :not_defined} ``` Calculates the week of the year from the given `year`, `month`, and `day`. By default this function always returns `{:error, :not_defined}`. # `weeks_in_year` Returns the number of weeks in a given `year`. # `year` Returns a `t:Date.Range.t/0` representing a given year. # `year_of_era` ```elixir @spec year_of_era(Calendar.year()) :: {year :: Calendar.year(), era :: Calendar.era()} @spec year_of_era(year()) :: {pos_integer(), 0..1} ``` Calculates the year and era from the given `year`. The Coptic calendar has two eras: the current era which starts in year 1 and is defined as era `1` (anno martyrum); and a second era for years less than 1, defined as era `0`. # `year_of_era` ```elixir @spec year_of_era(Calendar.year(), Calendar.month(), Calendar.day()) :: {year :: Calendar.year(), era :: Calendar.era()} ``` Calculates the year and era from the given `date`. --- *Consult [api-reference.md](api-reference.md) for complete listing*