Calendar behaviour

This module defines the responsibilities for working with calendars, dates, times and datetimes in Elixir.

Currently it defines types and the minimal implementation for a calendar behaviour in Elixir. The goal of the Calendar features in Elixir is to provide a base for interoperatibility instead of full-featured datetime API.

For the actual date, time and datetime structures, see Date, Time, NaiveDateTime and DateTime.

Note the year, month, day, etc designations are overspecified (i.e. an integer instead of 1..12 for months) because different calendars may have a different number of days per month, months per year and so on.

Summary

Types

calendar(): A calendar implementation
day()
hour()
microsecond(): Microseconds with stored precision
minute()
month()
second(): From 0 to 60 to account for leap seconds
std_offset(): The time zone standard offset in seconds (not zero in summer times)
time_zone(): The time zone ID according to the IANA tz database (e.g. Europe/Zurich)
utc_offset(): The time zone UTC offset in seconds
year()
zone_abbr(): The time zone abbreviation (e.g. CET or CEST or BST etc.)

Callbacks

date(year, month, day): Builds a new date from proleptic year, month and day of month
leap_year?(year): Returns true if the given year is a leap year
to_string(arg0): Converts the given structure into a string according to the calendar

Types

calendar()

calendar() :: module

A calendar implementation

day()

day() :: integer

hour()

hour() :: 0..23

microsecond()

microsecond() :: {0..999999, 0..6}

Microseconds with stored precision.

The precision represents the number of digits that must be used when representing the microseconds to external format. If the precision is 0, it means microseconds must be skipped.

minute()

minute() :: 0..59

month()

month() :: integer

second()

second() :: 0..60

From 0 to 60 to account for leap seconds

std_offset()

std_offset() :: integer

The time zone standard offset in seconds (not zero in summer times)

time_zone()

time_zone() :: String.t

The time zone ID according to the IANA tz database (e.g. Europe/Zurich)

utc_offset()

utc_offset() :: integer

The time zone UTC offset in seconds

year()

year() :: integer

zone_abbr()

zone_abbr() :: String.t

The time zone abbreviation (e.g. CET or CEST or BST etc.)

Callbacks

date(year, month, day)

date(year, month, day) :: {:ok, Date.t} | {:error, atom}

Builds a new date from proleptic year, month and day of month.

leap_year?(year)

leap_year?(year) :: boolean

Returns true if the given year is a leap year.

A leap year is a year of a longer length than normal. The exact meaning is up to the calendar. A calendar must return false if it does not support the concept of leap years.

to_string(arg0)

to_string(Date.t | NaiveDateTime.t | DateTime.t) :: String.t

Converts the given structure into a string according to the calendar.