Calendar.ISO (Elixir v1.13.0-dev) View Source

The default calendar implementation, a Gregorian calendar following ISO 8601.

This calendar implements a 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.

ISO 8601 compliance

The ISO 8601 specification is feature-rich, but allows applications to selectively implement most parts of it. The choices Elixir makes are catalogued below.

Features

The standard library supports a minimal set of possible ISO 8601 features. Specifically, the parser only supports calendar dates and does not support ordinal and week formats.

By default Elixir only parses extended-formatted date/times. You can opt-in to parse basic-formatted date/times.

NaiveDateTime.to_iso8601/2 and DateTime.to_iso8601/2 allow you to produce either basic or extended formatted strings, and Calendar.strftime/2 allows you to format datetimes however else you desire.

Elixir does not support reduced accuracy formats (for example, a date without the day component) nor decimal precisions in the lowest component (such as 10:01:25,5). No functions exist to parse ISO 8601 durations or time intervals.

Examples

Elixir expects the extended format by default when parsing:

iex> Calendar.ISO.parse_naive_datetime("2015-01-23T23:50:07")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_naive_datetime("20150123T235007")
{:error, :invalid_format}

Parsing can be restricted to basic if desired:

iex> Calendar.ISO.parse_naive_datetime("20150123T235007Z", :basic)
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_naive_datetime("20150123T235007Z", :extended)
{:error, :invalid_format}

Only calendar dates are supported in parsing; ordinal and week dates are not.

iex> Calendar.ISO.parse_date("2015-04-15")
{:ok, {2015, 4, 15}}
iex> Calendar.ISO.parse_date("2015-105")
{:error, :invalid_format}
iex> Calendar.ISO.parse_date("2015-W16")
{:error, :invalid_format}
iex> Calendar.ISO.parse_date("2015-W016-3")
{:error, :invalid_format}

Years, months, days, hours, minutes, and seconds must be fully specified:

iex> Calendar.ISO.parse_date("2015-04-15")
{:ok, {2015, 4, 15}}
iex> Calendar.ISO.parse_date("2015-04")
{:error, :invalid_format}
iex> Calendar.ISO.parse_date("2015")
{:error, :invalid_format}

iex> Calendar.ISO.parse_time("23:50:07.0123456")
{:ok, {23, 50, 7, {12345, 6}}}
iex> Calendar.ISO.parse_time("23:50:07")
{:ok, {23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_time("23:50")
{:error, :invalid_format}
iex> Calendar.ISO.parse_time("23")
{:error, :invalid_format}

Extensions

The parser and formatter adopt one ISO 8601 extension: extended year notation.

This allows dates to be prefixed with a + or - sign, extending the range of expressible years from the default (0000..9999) to -9999..9999. Elixir still restricts years in this format to four digits.

Examples

iex> Calendar.ISO.parse_date("-2015-01-23")
{:ok, {-2015, 1, 23}}
iex> Calendar.ISO.parse_date("+2015-01-23")
{:ok, {2015, 1, 23}}

iex> Calendar.ISO.parse_naive_datetime("-2015-01-23 23:50:07")
{:ok, {-2015, 1, 23, 23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_naive_datetime("+2015-01-23 23:50:07")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}

iex> Calendar.ISO.parse_utc_datetime("-2015-01-23 23:50:07Z")
{:ok, {-2015, 1, 23, 23, 50, 7, {0, 0}}, 0}
iex> Calendar.ISO.parse_utc_datetime("+2015-01-23 23:50:07Z")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}, 0}

Additions

ISO 8601 does not allow a whitespace instead of T as a separator between date and times, both when parsing and formatting. This is a common enough representation, Elixir allows it during parsing.

The formatting of dates in NaiveDateTime.to_iso8601/1 and DateTime.to_iso8601/1 do produce specification-compliant string representations using the T separator.

Examples

iex> Calendar.ISO.parse_naive_datetime("2015-01-23 23:50:07.0123456")
{:ok, {2015, 1, 23, 23, 50, 7, {12345, 6}}}
iex> Calendar.ISO.parse_naive_datetime("2015-01-23T23:50:07.0123456")
{:ok, {2015, 1, 23, 23, 50, 7, {12345, 6}}}

iex> Calendar.ISO.parse_utc_datetime("2015-01-23 23:50:07.0123456Z")
{:ok, {2015, 1, 23, 23, 50, 7, {12345, 6}}, 0}
iex> Calendar.ISO.parse_utc_datetime("2015-01-23T23:50:07.0123456Z")
{:ok, {2015, 1, 23, 23, 50, 7, {12345, 6}}, 0}

Link to this section Summary

Types

"Before the Current Era" or "Before the Common Era" (BCE), for those years less than 1.

The "Current Era" or the "Common Era" (CE) which starts in year 1.

Integer that represents the day of the week, where 1 is Monday and 7 is Sunday.

The calendar era.

Microseconds with stored precision.

Functions

Converts the given date into a string.

Calculates the day and era from the given year, month, and day.

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

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

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

Returns if the given year is a leap year.

Returns how many months there are in the given year.

Converts the Calendar.iso_days/0 format to the datetime format specified by this calendar.

Parses a date string in the :extended format.

Parses a date string according to a given format.

Parses a naive datetime string in the :extended format.

Parses a naive datetime string according to a given format.

Parses a time string in the :extended format.

Parses a time string according to a given format.

Parses a UTC datetime string in the :extended format.

Parses a UTC datetime string according to a given format.

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

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

Returns the normalized day fraction of the specified time.

Determines if the date given is valid according to the proleptic Gregorian calendar.

Determines if the date given is valid according to the proleptic Gregorian calendar.

Calculates the year and era from the given year.

Calendar callback to compute the year and era from the given year, month and day.

Link to this section Types

Specs

bce() :: 0

"Before the Current Era" or "Before the Common Era" (BCE), for those years less than 1.

Specs

ce() :: 1

The "Current Era" or the "Common Era" (CE) which starts in year 1.

Specs

day() :: 1..31

Specs

day_of_week() :: 1..7

Integer that represents the day of the week, where 1 is Monday and 7 is Sunday.

Specs

day_of_year() :: 1..366

Specs

era() :: bce() | ce()

The calendar era.

The ISO calendar has two eras:

  • CE - which starts in year 1 and is defined as era 1.
  • BCE - for those years less than 1 and is defined as era 0.

Specs

format() :: :basic | :extended

Specs

hour() :: 0..23

Specs

microsecond() :: {0..999_999, 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.

Specs

minute() :: 0..59

Specs

month() :: 1..12

Specs

quarter_of_year() :: 1..4

Specs

second() :: 0..59

Specs

utc_offset() :: integer()

Specs

weekday() ::
  :monday | :tuesday | :wednesday | :thursday | :friday | :saturday | :sunday

Specs

year() :: -9999..9999

Specs

year_of_era() :: {1..10000, era()}

Link to this section Functions

Link to this function

date_to_string(year, month, day, format \\ :extended)

View Source (since 1.4.0)

Specs

date_to_string(year(), month(), day(), :basic | :extended) :: String.t()

Converts the given date into a string.

By default, returns dates formatted in the "extended" format, for human readability. It also supports the "basic" format by passing the :basic option.

Examples

iex> Calendar.ISO.date_to_string(2015, 2, 28)
"2015-02-28"
iex> Calendar.ISO.date_to_string(2017, 8, 1)
"2017-08-01"
iex> Calendar.ISO.date_to_string(-99, 1, 31)
"-0099-01-31"

iex> Calendar.ISO.date_to_string(2015, 2, 28, :basic)
"20150228"
iex> Calendar.ISO.date_to_string(-99, 1, 31, :basic)
"-00990131"
Link to this function

datetime_to_string(year, month, day, hour, minute, second, microsecond, time_zone, zone_abbr, utc_offset, std_offset, format \\ :extended)

View Source (since 1.4.0)

Specs

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

By default, returns datetimes formatted in the "extended" format, for human readability. It also supports the "basic" format by passing the :basic option.

Examples

iex> time_zone = "Etc/UTC"
iex> Calendar.ISO.datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5}, time_zone, "UTC", 0, 0)
"2017-08-01 01:02:03.00000Z"
iex> Calendar.ISO.datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5}, time_zone, "UTC", 3600, 0)
"2017-08-01 01:02:03.00000+01:00"
iex> Calendar.ISO.datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5}, time_zone, "UTC", 3600, 3600)
"2017-08-01 01:02:03.00000+02:00"

iex> time_zone = "Europe/Berlin"
iex> Calendar.ISO.datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5}, time_zone, "CET", 3600, 0)
"2017-08-01 01:02:03.00000+01:00 CET Europe/Berlin"
iex> Calendar.ISO.datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5}, time_zone, "CDT", 3600, 3600)
"2017-08-01 01:02:03.00000+02:00 CDT Europe/Berlin"

iex> time_zone = "America/Los_Angeles"
iex> Calendar.ISO.datetime_to_string(2015, 2, 28, 1, 2, 3, {4, 5}, time_zone, "PST", -28800, 0)
"2015-02-28 01:02:03.00000-08:00 PST America/Los_Angeles"
iex> Calendar.ISO.datetime_to_string(2015, 2, 28, 1, 2, 3, {4, 5}, time_zone, "PDT", -28800, 3600)
"2015-02-28 01:02:03.00000-07:00 PDT America/Los_Angeles"

iex> time_zone = "Europe/Berlin"
iex> Calendar.ISO.datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5}, time_zone, "CET", 3600, 0, :basic)
"20170801 010203.00000+0100 CET Europe/Berlin"
Link to this function

day_of_era(year, month, day)

View Source (since 1.8.0)

Specs

day_of_era(year(), month(), day()) :: Calendar.day_of_era()

Calculates the day and era from the given year, month, and day.

Examples

iex> Calendar.ISO.day_of_era(0, 1, 1)
{366, 0}
iex> Calendar.ISO.day_of_era(1, 1, 1)
{1, 1}
iex> Calendar.ISO.day_of_era(0, 12, 31)
{1, 0}
iex> Calendar.ISO.day_of_era(0, 12, 30)
{2, 0}
iex> Calendar.ISO.day_of_era(-1, 12, 31)
{367, 0}
Link to this function

day_of_week(year, month, day, starting_on)

View Source (since 1.11.0)

Specs

day_of_week(year(), month(), day(), :default | weekday()) ::
  {day_of_week(), 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 the given starting_on weekday. For example, if starting_on is set to :monday, then 1 is Monday and 7 is Sunday.

starting_on can also be :default, which is equivalent to :monday.

Examples

iex> Calendar.ISO.day_of_week(2016, 10, 31, :monday)
{1, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 1, :monday)
{2, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 2, :monday)
{3, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 3, :monday)
{4, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 4, :monday)
{5, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 5, :monday)
{6, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 6, :monday)
{7, 1, 7}
iex> Calendar.ISO.day_of_week(-99, 1, 31, :monday)
{4, 1, 7}

iex> Calendar.ISO.day_of_week(2016, 10, 31, :sunday)
{2, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 1, :sunday)
{3, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 2, :sunday)
{4, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 3, :sunday)
{5, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 4, :sunday)
{6, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 5, :sunday)
{7, 1, 7}
iex> Calendar.ISO.day_of_week(2016, 11, 6, :sunday)
{1, 1, 7}
iex> Calendar.ISO.day_of_week(-99, 1, 31, :sunday)
{5, 1, 7}

iex> Calendar.ISO.day_of_week(2016, 10, 31, :saturday)
{3, 1, 7}
Link to this function

day_of_year(year, month, day)

View Source (since 1.8.0)

Specs

day_of_year(year(), month(), day()) :: day_of_year()

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

It is an integer from 1 to 366.

Examples

iex> Calendar.ISO.day_of_year(2016, 1, 31)
31
iex> Calendar.ISO.day_of_year(-99, 2, 1)
32
iex> Calendar.ISO.day_of_year(2018, 2, 28)
59
Link to this function

day_rollover_relative_to_midnight_utc()

View Source (since 1.5.0)

Specs

day_rollover_relative_to_midnight_utc() :: {0, 1}

See Calendar.day_rollover_relative_to_midnight_utc/0 for documentation.

Link to this function

days_in_month(year, month)

View Source (since 1.4.0)

Specs

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
iex> Calendar.ISO.days_in_month(-1, 5)
31
Link to this function

leap_year?(year)

View Source (since 1.3.0)

Specs

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
iex> Calendar.ISO.leap_year?(-4)
true
Link to this function

months_in_year(year)

View Source (since 1.7.0)

Specs

months_in_year(year()) :: 12

Returns how many months there are in the given year.

Example

iex> Calendar.ISO.months_in_year(2004)
12
Link to this function

naive_datetime_from_iso_days(arg)

View Source (since 1.5.0)

Specs

Converts the Calendar.iso_days/0 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({730_485, {0, 86400}})
{2000, 1, 1, 0, 0, 0, {0, 6}}
iex> Calendar.ISO.naive_datetime_from_iso_days({730_485, {43200, 86400}})
{2000, 1, 1, 12, 0, 0, {0, 6}}
iex> Calendar.ISO.naive_datetime_from_iso_days({-365, {0, 86400000000}})
{-1, 1, 1, 0, 0, 0, {0, 6}}
Link to this function

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

View Source (since 1.5.0)

Specs

Returns the Calendar.iso_days/0 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}}
iex> Calendar.ISO.naive_datetime_to_iso_days(-1, 1, 1, 0, 0, 0, {0, 6})
{-365, {0, 86400000000}}
Link to this function

naive_datetime_to_string(year, month, day, hour, minute, second, microsecond, format \\ :extended)

View Source (since 1.4.0)

Specs

naive_datetime_to_string(
  year(),
  month(),
  day(),
  Calendar.hour(),
  Calendar.minute(),
  Calendar.second(),
  Calendar.microsecond(),
  :basic | :extended
) :: String.t()

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

By default, returns datetimes formatted in the "extended" format, for human readability. It also supports the "basic" format by passing the :basic option.

Examples

iex> Calendar.ISO.naive_datetime_to_string(2015, 2, 28, 1, 2, 3, {4, 6})
"2015-02-28 01:02:03.000004"
iex> Calendar.ISO.naive_datetime_to_string(2017, 8, 1, 1, 2, 3, {4, 5})
"2017-08-01 01:02:03.00000"

iex> Calendar.ISO.naive_datetime_to_string(2015, 2, 28, 1, 2, 3, {4, 6}, :basic)
"20150228 010203.000004"
Link to this function

parse_date(string)

View Source (since 1.10.0)

Specs

parse_date(String.t()) :: {:ok, {year(), month(), day()}} | {:error, atom()}

Parses a date string in the :extended format.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_date("2015-01-23")
{:ok, {2015, 1, 23}}

iex> Calendar.ISO.parse_date("2015:01:23")
{:error, :invalid_format}
iex> Calendar.ISO.parse_date("2015-01-32")
{:error, :invalid_date}
Link to this function

parse_date(string, format)

View Source (since 1.12.0)

Specs

parse_date(String.t(), format()) ::
  {:ok, {year(), month(), day()}} | {:error, atom()}

Parses a date string according to a given format.

The format can either be :basic or :extended.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_date("20150123", :basic)
{:ok, {2015, 1, 23}}
iex> Calendar.ISO.parse_date("20150123", :extended)
{:error, :invalid_format}
Link to this function

parse_naive_datetime(string)

View Source (since 1.10.0)

Specs

parse_naive_datetime(String.t()) ::
  {:ok, {year(), month(), day(), hour(), minute(), second(), microsecond()}}
  | {:error, atom()}

Parses a naive datetime string in the :extended format.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_naive_datetime("2015-01-23 23:50:07")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_naive_datetime("2015-01-23 23:50:07Z")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_naive_datetime("2015-01-23 23:50:07-02:30")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}

iex> Calendar.ISO.parse_naive_datetime("2015-01-23 23:50:07.0")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 1}}}
iex> Calendar.ISO.parse_naive_datetime("2015-01-23 23:50:07,0123456")
{:ok, {2015, 1, 23, 23, 50, 7, {12345, 6}}}
Link to this function

parse_naive_datetime(string, format)

View Source (since 1.12.0)

Specs

parse_naive_datetime(String.t(), format()) ::
  {:ok, {year(), month(), day(), hour(), minute(), second(), microsecond()}}
  | {:error, atom()}

Parses a naive datetime string according to a given format.

The format can either be :basic or :extended.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_naive_datetime("20150123 235007", :basic)
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_naive_datetime("20150123 235007", :extended)
{:error, :invalid_format}
Link to this function

parse_time(string)

View Source (since 1.10.0)

Specs

parse_time(String.t()) ::
  {:ok, {hour(), minute(), second(), microsecond()}} | {:error, atom()}

Parses a time string in the :extended format.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_time("23:50:07")
{:ok, {23, 50, 7, {0, 0}}}

iex> Calendar.ISO.parse_time("23:50:07Z")
{:ok, {23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_time("T23:50:07Z")
{:ok, {23, 50, 7, {0, 0}}}
Link to this function

parse_time(string, format)

View Source (since 1.12.0)

Specs

parse_time(String.t(), format()) ::
  {:ok, {hour(), minute(), second(), microsecond()}} | {:error, atom()}

Parses a time string according to a given format.

The format can either be :basic or :extended.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_time("235007", :basic)
{:ok, {23, 50, 7, {0, 0}}}
iex> Calendar.ISO.parse_time("235007", :extended)
{:error, :invalid_format}
Link to this function

parse_utc_datetime(string)

View Source (since 1.10.0)

Specs

parse_utc_datetime(String.t()) ::
  {:ok, {year(), month(), day(), hour(), minute(), second(), microsecond()},
   utc_offset()}
  | {:error, atom()}

Parses a UTC datetime string in the :extended format.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_utc_datetime("2015-01-23 23:50:07Z")
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}, 0}

iex> Calendar.ISO.parse_utc_datetime("2015-01-23 23:50:07+02:30")
{:ok, {2015, 1, 23, 21, 20, 7, {0, 0}}, 9000}

iex> Calendar.ISO.parse_utc_datetime("2015-01-23 23:50:07")
{:error, :missing_offset}
Link to this function

parse_utc_datetime(string, format)

View Source (since 1.12.0)

Specs

parse_utc_datetime(String.t(), format()) ::
  {:ok, {year(), month(), day(), hour(), minute(), second(), microsecond()},
   utc_offset()}
  | {:error, atom()}

Parses a UTC datetime string according to a given format.

The format can either be :basic or :extended.

For more information on supported strings, see how this module implements ISO 8601.

Examples

iex> Calendar.ISO.parse_utc_datetime("20150123 235007Z", :basic)
{:ok, {2015, 1, 23, 23, 50, 7, {0, 0}}, 0}
iex> Calendar.ISO.parse_utc_datetime("20150123 235007Z", :extended)
{:error, :invalid_format}
Link to this function

quarter_of_year(year, month, day)

View Source (since 1.8.0)

Specs

quarter_of_year(year(), month(), day()) :: quarter_of_year()

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

It is an integer from 1 to 4.

Examples

iex> Calendar.ISO.quarter_of_year(2016, 1, 31)
1
iex> Calendar.ISO.quarter_of_year(2016, 4, 3)
2
iex> Calendar.ISO.quarter_of_year(-99, 9, 31)
3
iex> Calendar.ISO.quarter_of_year(2018, 12, 28)
4
Link to this function

time_from_day_fraction(arg)

View Source (since 1.5.0)

Specs

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

View Source (since 1.5.0)

Specs

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}
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time_to_string(hour, minute, second, microsecond, format \\ :extended)

View Source (since 1.5.0)

Specs

time_to_string(
  Calendar.hour(),
  Calendar.minute(),
  Calendar.second(),
  Calendar.microsecond(),
  :basic | :extended
) :: String.t()

Converts the given time into a string.

By default, returns times formatted in the "extended" format, for human readability. It also supports the "basic" format by passing the :basic option.

Examples

iex> Calendar.ISO.time_to_string(2, 2, 2, {2, 6})
"02:02:02.000002"
iex> Calendar.ISO.time_to_string(2, 2, 2, {2, 2})
"02:02:02.00"
iex> Calendar.ISO.time_to_string(2, 2, 2, {2, 0})
"02:02:02"

iex> Calendar.ISO.time_to_string(2, 2, 2, {2, 6}, :basic)
"020202.000002"
iex> Calendar.ISO.time_to_string(2, 2, 2, {2, 6}, :extended)
"02:02:02.000002"
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valid_date?(year, month, day)

View Source (since 1.5.0)

Specs

valid_date?(year(), month(), day()) :: boolean()

Determines if the date given is valid according to the proleptic Gregorian calendar.

Examples

iex> Calendar.ISO.valid_date?(2015, 2, 28)
true
iex> Calendar.ISO.valid_date?(2015, 2, 30)
false
iex> Calendar.ISO.valid_date?(-1, 12, 31)
true
iex> Calendar.ISO.valid_date?(-1, 12, 32)
false
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valid_time?(hour, minute, second, microsecond)

View Source (since 1.5.0)

Specs

Determines if the date given is valid according to the proleptic Gregorian calendar.

Leap seconds are not supported by the built-in Calendar.ISO.

Examples

iex> Calendar.ISO.valid_time?(10, 50, 25, {3006, 6})
true
iex> Calendar.ISO.valid_time?(23, 59, 60, {0, 0})
false
iex> Calendar.ISO.valid_time?(24, 0, 0, {0, 0})
false
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year_of_era(year)

View Source (since 1.8.0)

Specs

year_of_era(year()) :: {1..10000, era()}

Calculates the year and era from the given year.

The ISO calendar has two eras: the "current era" (CE) which starts in year 1 and is defined as era 1. And "before the current era" (BCE) for those years less than 1, defined as era 0.

Examples

iex> Calendar.ISO.year_of_era(1)
{1, 1}
iex> Calendar.ISO.year_of_era(2018)
{2018, 1}
iex> Calendar.ISO.year_of_era(0)
{1, 0}
iex> Calendar.ISO.year_of_era(-1)
{2, 0}
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year_of_era(year, month, day)

View Source (since 1.13.0)

Specs

year_of_era(year(), month(), day()) :: {1..10000, era()}

Calendar callback to compute the year and era from the given year, month and day.

In the ISO calendar, the new year coincides with the new era, so the month and day arguments are discarded. If you only have the year available, you can year_of_era/1 instead.

Examples

iex> Calendar.ISO.year_of_era(1, 1, 1)
{1, 1}
iex> Calendar.ISO.year_of_era(2018, 12, 1)
{2018, 1}
iex> Calendar.ISO.year_of_era(0, 1, 1)
{1, 0}
iex> Calendar.ISO.year_of_era(-1, 12, 1)
{2, 0}