icu_format_date (input date, format text [,locale text])

Return the string representing the input date with the given format and locale as described above. If locale is not specified, the current ICU locale is used.

Example: ```sql => select icu_format_date('2020-12-31'::date, '{medium}', 'en@calendar=ethiopic');

icu_format_date

icu_format_datetime (input timestamptz, format text [,locale text])

Return the string representing the time stamp wih time zone tswith the given format and locale as described above. If locale is not specified, the current ICU locale is used.

Example:

=> SELECT icu_format_datetime(
     now(),
     'GGGG dd/MMMM/yyyy HH:mm:ss.SSS z',
     'fr@calendar=buddhist'
   );
              icu_format_datetime
------------------------------------------------
 ère bouddhique 22/septembre/2566 14:55:48.133 UTC+2

icu_parse_date (input text, format text [,locale text])

Return a date resulting from parsing the input string according to format (see "format strings" above).

The function will error out if the input string interpreted with the given format and locale does not strictly match the format or cannot be converted into a date. When locale is not specified, the current ICU locale is used.

Example:

=> SET icu_ext.locale TO '@calendar=buddhist';
=> SELECT icu_parse_date('25/09/2566', 'dd/MM/yyyy');
 icu_parse_date 
----------------
 2023-09-25

icu_parse_datetime (input text, format text [,locale text])

Return a timestamp with time zone resulting from parsing the input string according to format. This is similar to icu_parse_date() except that it parses a full timestamp instead of a date.

Example:

=> SELECT icu_parse_datetime(
  '11/Meskerem/2016 14:57:17',
  'dd/MMMM/yyyy HH:mm:ss',
  'en@calendar=ethiopic'
); 
   icu_parse_datetime   
------------------------
 2023-09-22 14:57:17+02

Custom types

icu_date

It differs from the core built-in type date in the input and output formats that are accepted. icu_date text representation works with respect to icu_ext.date_format if set, and otherwise with the default format of the current ICU locale. To express non-finite dates, use 'infinity'::date::icu_date.

Internally, the representation is the same as the date type, and icu_date can be cast implicitly to and from date.

Example: ```sql CREATE TABLE events(ev_name text, ev_date icu_date);

INSERT INTO events VALUES('birthday', '2023-07-31'::date);

SET icu_ext.locale TO 'orm@calendar=ethiopic';

SELECT * FROM events;

+----------+--------------------+ | ev_name | ev_date | +----------+--------------------+ | birthday | 24-Hamle-2015 ERA1 | +----------+--------------------+

```

icu_timestamptz

It differs from the core built-in type timestamp with time zone (or timestamptz in short) in the input and output formats that are accepted. The text representation for icu_timestamptz works with respect to icu_ext.timestamp_format if set, and otherwise with the default format of the current ICU locale. To express non-finite timestamps, use 'infinity'::timestamptz::icu_timestamptz.

Internally, the representation is the same as the timestamptz type, and icu_timestamptz can be cast directly to and from timestamptz.

icu_interval

Like the interval built-in data type, it represents spans of time with years, months, days and microseconds components that are meant to process calendar-aware calculations.

It differs from interval in not assuming that one year always equals 12 months. For instance, in the ethiopic calendar, there are 13 months in a year. How spans of time are added to dates and timestamps depend on the current calendar. icu_interval accepts the same textual inputs as the interval data type. It also shares pretty much the same output except for not converting months to years.

icu_interval can be cast from interval.

Example: ```sql select '25 months'::interval, '25 months'::icu_interval; +---------------+--------------+ | interval | icu_interval | +---------------+--------------+ | 2 years 1 mon | 25 mons | +---------------+--------------+

```

Operators

icu_interval * int

Multiply each component of the interval (years, months...) by the integer number. This operator is commutative.

icu_date + icu_interval

Add the years, months, days and time from the interval to the date, with respect to the rules of the calendar of the current locale (icu_ext.locale).

icu_date - icu_interval

Substract the years, months, days and time from the interval to the date, with respect to the rules of the calendar of the current locale (icu_ext.locale).

icu_timestamptz + icu_interval

Add the years, months, days and time from the interval to the timestamp, with respect to the rules of the calendar of the current locale (icu_ext.locale).

This operator is commutative.

icu_timestamptz - icu_interval

Subtract the years, months, days and time from the interval to the timestamp, with respect to the rules of the calendar of the current locale (icu_ext.locale).

icu_interval + icu_interval

Add the intervals. The result does not depend on the current calendar.

icu_interval - icu_interval

Subtract the intervals. The result does not depend on the current calendar.

Configurable settings

There are three configuration settings that work together to control input and output of the icu_date and icu_timestamptz types.

icu_ext.locale

Locale to use for input/output and calendar-dependent calculations, as described in "Locale format and settings" above.

``` -- vietnamese language, buddhist calendar SET icu_ext.locale TO 'vi@calendar=buddhist';

SET icu_ext.timestamptz_format TO '{long}';

SELECT now()::icu_timestamptz;

now

Ngày 22 tháng 9 năm 2566 BE lúc 15:57:13 GMT+2

```

icu_ext.date_format