Calendar.ISO

A calendar implementation that follows to ISO 8601.

This calendar implements the proleptic Gregorian calendar and is therefore compatible with the calendar used in most countries today. The proleptic means the Gregorian rules for leap years are applied for all time, consequently the dates give different results before the year 1583 from when the Gregorian calendar was adopted.

Note that while ISO 8601 allows times and datetimes to specify 24:00:00 as the zero hour of the next day, this notation is not supported by Elixir.

Summary

Types

day()

month()

year()

Functions

date_to_string(year, month, day)

Converts the given date into a string

datetime_to_string(year, month, day, hour, minute, second, microsecond, time_zone, zone_abbr, utc_offset, std_offset)

Convers the datetime (with time zone) into a string

day_of_week(year, month, day)

Calculates the day of the week from the given year, month, and day

days_in_month(year, month)

Returns how many days there are in the given year-month

leap_year?(year)

Returns if the given year is a leap year

naive_datetime_from_iso_days(arg)

Converts the t:Calendar.iso_days format to the datetime format specified by this calendar

naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond)

Returns the t:Calendar.iso_days format of the specified date

naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)

Converts the datetime (without time zone) into a string

time_from_day_fraction(arg)

Converts a day fraction to this Calendar’s representation of time

time_to_day_fraction(hour, minute, second, arg)

Returns the normalized day fraction of the specified time

time_to_string(hour, minute, second, microsecond)

Converts the given time into a string

time_to_string(hour, minute, second, arg, format)

Types

day()

day() :: 1..31

month()

month() :: 1..12

year()

year() :: 0..9999

Functions

date_to_string(year, month, day)

Converts the given date into a string.

datetime_to_string(year, month, day, hour, minute, second, microsecond, time_zone, zone_abbr, utc_offset, std_offset)

Convers the datetime (with time zone) into a string.

day_of_week(year, month, day)

day_of_week(year(), month(), day()) :: 1..7

Calculates the day of the week from the given year, month, and day.

It is an integer from 1 to 7, where 1 is Monday and 7 is Sunday.

Examples

iex> Calendar.ISO.day_of_week(2016, 10, 31)
1
iex> Calendar.ISO.day_of_week(2016, 11, 01)
2
iex> Calendar.ISO.day_of_week(2016, 11, 02)
3
iex> Calendar.ISO.day_of_week(2016, 11, 03)
4
iex> Calendar.ISO.day_of_week(2016, 11, 04)
5
iex> Calendar.ISO.day_of_week(2016, 11, 05)
6
iex> Calendar.ISO.day_of_week(2016, 11, 06)
7

days_in_month(year, month)

days_in_month(year(), month()) :: 28..31

Returns how many days there are in the given year-month.

Examples

iex> Calendar.ISO.days_in_month(1900, 1)
31
iex> Calendar.ISO.days_in_month(1900, 2)
28
iex> Calendar.ISO.days_in_month(2000, 2)
29
iex> Calendar.ISO.days_in_month(2001, 2)
28
iex> Calendar.ISO.days_in_month(2004, 2)
29
iex> Calendar.ISO.days_in_month(2004, 4)
30

leap_year?(year)

leap_year?(year()) :: boolean()

Returns if the given year is a leap year.

Examples

iex> Calendar.ISO.leap_year?(2000)
true
iex> Calendar.ISO.leap_year?(2001)
false
iex> Calendar.ISO.leap_year?(2004)
true
iex> Calendar.ISO.leap_year?(1900)
false

naive_datetime_from_iso_days(arg)

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.

Examples

iex> Calendar.ISO.naive_datetime_from_iso_days({0, {0, 86400}})
{0, 1, 1, 0, 0, 0, {0, 6}}
iex> Calendar.ISO.naive_datetime_from_iso_days({730485, {0, 86400}})
{2000, 1, 1, 0, 0, 0, {0, 6}}
iex> Calendar.ISO.naive_datetime_from_iso_days({730485, {43200, 86400}})
{2000, 1, 1, 12, 0, 0, {0, 6}}

naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond)

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.

Examples

iex> Calendar.ISO.naive_datetime_to_iso_days(0, 1, 1, 0, 0, 0, {0, 6})
{0, {0, 86400000000}}
iex> Calendar.ISO.naive_datetime_to_iso_days(2000, 1, 1, 12, 0, 0, {0, 6})
{730485, {43200000000, 86400000000}}
iex> Calendar.ISO.naive_datetime_to_iso_days(2000, 1, 1, 13, 0, 0, {0, 6})
{730485, {46800000000, 86400000000}}

naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)

Converts the datetime (without time zone) into a string.

time_from_day_fraction(arg)

time_from_day_fraction(Calendar.day_fraction()) ::
  {Calendar.hour(), Calendar.minute(), Calendar.second(),
   Calendar.microsecond()}

Converts a day fraction to this Calendar’s representation of time.

Examples

iex> Calendar.ISO.time_from_day_fraction({1,2})
{12, 0, 0, {0, 6}}
iex> Calendar.ISO.time_from_day_fraction({13,24})
{13, 0, 0, {0, 6}}

time_to_day_fraction(hour, minute, second, arg)

time_to_day_fraction(
  Calendar.hour(),
  Calendar.minute(),
  Calendar.second(),
  Calendar.microsecond()
) :: Calendar.day_fraction()

Returns the normalized day fraction of the specified time.

Examples

iex> Calendar.ISO.time_to_day_fraction(0, 0, 0, {0, 6})
{0, 86400000000}
iex> Calendar.ISO.time_to_day_fraction(12, 34, 56, {123, 6})
{45296000123, 86400000000}

time_to_string(hour, minute, second, microsecond)

Converts the given time into a string.

time_to_string(hour, minute, second, arg, format)