Returns the format code representing the date or time unit that is the greatest difference between two date/times.

Arguments

• from is any DateTime.t/0 or t:NaiveDateTine.t/0

• to is any DateTime.t/0 or t:NaiveDateTine.t/0

Returns

• {:ok, format_code} where format_code is one of

  • :y meaning that the greatest difference is in the year
  • :M meaning that the greatest difference is in the month
  • :d meaning that the greatest difference is in the day
  • :H meaning that the greatest difference is in the hour
  • :m meaning that the greatest difference is in the minute

• {:error, :no_practical_difference}

Example

iex> Cldr.DateTime.Interval.greatest_difference ~U[2022-04-22 02:00:00.0Z], ~U[2022-04-22 03:00:00.0Z]
{:ok, :H}

iex> Cldr.DateTime.Interval.greatest_difference ~U[2022-04-22 02:00:00.0Z], ~U[2022-04-22 02:00:01.0Z]
{:error, :no_practical_difference}

@spec to_string(
  Calendar.datetime() | nil,
  Calendar.datetime() | nil,
  Cldr.backend(),
  Keyword.t()
) ::
  {:ok, String.t()} | {:error, {module(), String.t()}}

Returns a localised string representing the formatted interval formed by two dates.

Arguments

• from is any map that conforms to the Calendar.datetime type.

• to is any map that conforms to the Calendar.datetime type. to must occur on or after from.

• backend is any module that includes use Cldr and is therefore a Cldr backend module

• options is a keyword list of options. The default is [].

Either of from or to may also be nil in which case the result is an "open" interval and the non-nil parameter is formatted using Cldr.DateTime.to_string/3.

Options

• :format is one of :short, :medium or :long or a specific format type or a string representation of an interval format. The default is :medium.

• :date_format is any one of :short, :medium, :long, :full. If defined, this option is used to format the date part of the date time. This option is only acceptable if the :format option is not specified, or is specified as either :short, :medium, :long, :full. If :date_format is not specified then the date format is defined by the :format option.

• :time_format is any one of :short, :medium, :long, :full. If defined, this option is used to format the time part of the date time. This option is only acceptable if the :format option is not specified, or is specified as either :short, :medium, :long, :full. If :time_format is not specified thenthe time format is defined by the :format option.

• :locale is any valid locale name returned by Cldr.known_locale_names/0 or a Cldr.LanguageTag.t/0 struct. The default is Cldr.get_locale/0

• :number_system a number system into which the formatted date digits should be transliterated.

• :prefer expresses the preference for one of the possible alternative sub-formats. See the variant preference notes below.

Variant Preference

• A small number of formats have one of two different alternatives, each with their own preference specifier. The preferences are specified with the :prefer option to Cldr.Date.to_string/3. The preference is expressed as an atom, or a list of one or two atoms with one atom being either :unicode or :ascii and one atom being either :default or :variant.

  • Some formats (at the time of publishng only time formats but that may change in the future) have :unicode and :ascii versions of the format. The difference is the use of ascii space (0x20) as a separateor in the :ascii verison whereas the :unicode version may use non-breaking or other space characters. The default is :unicode and this is the strongly preferred option. The :ascii format is primarily to support legacy use cases and is not recommended. See Cldr.Date.available_formats/3 to see which formats have these variants.

  • Some formats (at the time of publishing, only date and datetime formats) have :default and :variant versions of the format. These variant formats are only included in a small number of locales. For example, the :"en-CA" locale, which has a :default format respecting typical Canadian formatting and a :variant that is more closely aligned to US formatting. The default is :default.

Returns

• {:ok, string} or

• {:error, {exception, reason}}

Notes

• For more information on interval format string see the Cldr.Interval.

• The available predefined formats that can be applied are the keys of the map returned by Cldr.DateTime.Format.interval_formats("en", :gregorian) where "en" can be replaced by any configuration locale name and :gregorian is the underlying CLDR calendar type.

• In the case where from and to are equal, a single date is formatted instead of an interval

Examples

iex> Cldr.DateTime.Interval.to_string ~U[2020-01-01 00:00:00.0Z],
...> ~U[2020-12-31 10:00:00.0Z], MyApp.Cldr
{:ok, "Jan 1, 2020, 12:00:00 AM – Dec 31, 2020, 10:00:00 AM"}

iex> Cldr.DateTime.Interval.to_string ~U[2020-01-01 00:00:00.0Z], nil, MyApp.Cldr
{:ok, "Jan 1, 2020, 12:00:00 AM –"}

@spec to_string!(CalendarInterval.t(), Cldr.backend(), Keyword.t()) ::
  String.t() | no_return()

Returns a localised string representing the formatted interval formed by two dates or raises an exception.

Arguments

• from is any map that conforms to the Calendar.datetime type.

• to is any map that conforms to the Calendar.datetime type. to must occur on or after from.

• backend is any module that includes use Cldr and is therefore a Cldr backend module.

• options is a keyword list of options. The default is [].

Options

• :format is one of :short, :medium or :long or a specific format type or a string representing of an interval format. The default is :medium.

• :date_format is any one of :short, :medium, :long, :full. If defined, this option is used to format the date part of the date time. This option is only acceptable if the :format option is not specified, or is specified as either :short, :medium, :long, :full. If :date_format is not specified then the date format is defined by the :format option.

• :time_format is any one of :short, :medium, :long, :full. If defined, this option is used to format the time part of the date time. This option is only acceptable if the :format option is not specified, or is specified as either :short, :medium, :long, :full. If :time_format is not specified then the time format is defined by the :format option.

• :locale is any valid locale name returned by Cldr.known_locale_names/0 or a Cldr.LanguageTag.t/0 struct. The default is Cldr.get_locale/0.

• :number_system a number system into which the formatted date digits should be transliterated.

• :prefer expresses the preference for one of the possible alternative sub-formats. See the variant preference notes below.

Variant Preference

• A small number of formats have one of two different alternatives, each with their own preference specifier. The preferences are specified with the :prefer option to Cldr.Date.to_string/3. The preference is expressed as an atom, or a list of one or two atoms with one atom being either :unicode or :ascii and one atom being either :default or :variant.

  • Some formats (at the time of publishng only time formats but that may change in the future) have :unicode and :ascii versions of the format. The difference is the use of ascii space (0x20) as a separateor in the :ascii verison whereas the :unicode version may use non-breaking or other space characters. The default is :unicode and this is the strongly preferred option. The :ascii format is primarily to support legacy use cases and is not recommended. See Cldr.Date.available_formats/3 to see which formats have these variants.

  • Some formats (at the time of publishing, only date and datetime formats) have :default and :variant versions of the format. These variant formats are only included in a small number of locales. For example, the :"en-CA" locale, which has a :default format respecting typical Canadian formatting and a :variant that is more closely aligned to US formatting. The default is :default.

Returns

• string or

• raises an exception

Notes

• For more information on interval format string see the Cldr.Interval.

• The available predefined formats that can be applied are the keys of the map returned by Cldr.DateTime.Format.interval_formats("en", :gregorian) where "en" can be replaced by any configuration locale name and :gregorian is the underlying CLDR calendar type.

• In the case where from and to are equal, a single date is formatted instead of an interval.

Examples

iex> use CalendarInterval
iex> Cldr.DateTime.Interval.to_string! ~I"2020-01-01 00:00/10:00", MyApp.Cldr
"Jan 1, 2020, 12:00:00 AM – 10:00:59 AM"

Returns a localised string representing the formatted interval formed by two dates or raises an exception.

Arguments

• from is any map that conforms to the Calendar.datetime type.

• to is any map that conforms to the Calendar.datetime type. to must occur on or after from.

• backend is any module that includes use Cldr and is therefore a Cldr backend module.

• options is a keyword list of options. The default is [].

Options

• :format is one of :short, :medium or :long or a specific format type or a string representation of an interval format. The default is :medium.

• :date_format is any one of :short, :medium, :long, :full. If defined, this option is used to format the date part of the date time. This option is only acceptable if the :format option is not specified, or is specified as either :short, :medium, :long, :full. If :date_format is not specified then the date format is defined by the :format option.

• :time_format is any one of :short, :medium, :long, :full. If defined, this option is used to format the time part of the date time. This option is only acceptable if the :format option is not specified, or is specified as either :short, :medium, :long, :full. If :time_format is not specified then the time format is defined by the :format option.

• :locale is any valid locale name returned by Cldr.known_locale_names/0 or a Cldr.LanguageTag.t/0 struct. The default is Cldr.get_locale/0.

• :number_system a number system into which the formatted date digits should be transliterated.

• :prefer expresses the preference for one of the possible alternative sub-formats. See the variant preference notes below.

Variant Preference

• A small number of formats have one of two different alternatives, each with their own preference specifier. The preferences are specified with the :prefer option to Cldr.Date.to_string/3. The preference is expressed as an atom, or a list of one or two atoms with one atom being either :unicode or :ascii and one atom being either :default or :variant.

  • Some formats (at the time of publishng only time formats but that may change in the future) have :unicode and :ascii versions of the format. The difference is the use of ascii space (0x20) as a separateor in the :ascii verison whereas the :unicode version may use non-breaking or other space characters. The default is :unicode and this is the strongly preferred option. The :ascii format is primarily to support legacy use cases and is not recommended. See Cldr.Date.available_formats/3 to see which formats have these variants.

  • Some formats (at the time of publishing, only date and datetime formats) have :default and :variant versions of the format. These variant formats are only included in a small number of locales. For example, the :"en-CA" locale, which has a :default format respecting typical Canadian formatting and a :variant that is more closely aligned to US formatting. The default is :default.

Returns

• string or

• raises an exception

Notes

• For more information on interval format string see the Cldr.Interval.

• The available predefined formats that can be applied are the keys of the map returned by Cldr.DateTime.Format.interval_formats("en", :gregorian) where "en" can be replaced by any configuration locale name and :gregorian is the underlying CLDR calendar type.

• In the case where from and to are equal, a single date is formatted instead of an interval

Examples

iex> Cldr.DateTime.Interval.to_string! ~U[2020-01-01 00:00:00.0Z],
...> ~U[2020-12-31 10:00:00.0Z], MyApp.Cldr
"Jan 1, 2020, 12:00:00 AM – Dec 31, 2020, 10:00:00 AM"