Localize datetime using encapsulated IntlDateFormatter functions

format_datetime.php

<?php
/**
 * Localize datetime using encapsulated IntlDateFormatter functions
 *
 * @param IntlCalendar|DateTimeInterface|array|string|int|float $datetime
 * @param array $args
 * @link https://www.php.net/manual/en/intldateformatter.format.php
 * @link https://www.php.net/manual/en/intldateformatter.create.php
 * @link https://www.php.net/manual/en/class.locale.php
 * @link https://unicode-org.github.io/icu/userguide/format_parse/datetime/#date-field-symbol-table
 * @return string|false
 */
function format_datetime($datetime, array $args = []) {
    $args += [
        'date_type' => IntlDateFormatter::SHORT,
        'time_type' => IntlDateFormatter::SHORT,
        'locale'    => substr(Locale::getDefault(), 0, 5) ?: NULL,
        'pattern'   => NULL,
        'timezone'  => NULL,
    ];
    extract($args);
    $formatter = datefmt_create($locale, $date_type, $time_type, $timezone, NULL, $pattern);
    return datefmt_format($formatter, $datetime);
}

function format_date($datetime, array $args = []) {
    $args += [
        'date_type' => IntlDateFormatter::SHORT,
        'time_type' => IntlDateFormatter::NONE,
    ];
    return format_datetime($datetime, $args);
}

function format_time($datetime, array $args = []) {
    $args += [
        'date_type' => IntlDateFormatter::NONE,
        'time_type' => IntlDateFormatter::SHORT,
    ];
    return format_datetime($datetime, $args);
}

datefmt_create() arguments

• https://www.php.net/manual/en/intldateformatter.create.php

datefmt_create(?string $locale, int $dateType = IntlDateFormatter::FULL, int $timeType = IntlDateFormatter::FULL, IntlTimeZone|DateTimeZone|string|null $timezone = null, IntlCalendar|int|null $calendar = null, ?string $pattern = null)

locale argument

• https://www.php.net/manual/en/function.setlocale

If NULL, it will lookup its default value in this order:

1. ini_get('intl.default_locale')
2. setlocale(LC_ALL, 0);
3. $LANG value from the set locale of the operating system.

date type argument

If NULL, it will select IntlDateFormatter::FULL.

• IntlDateFormatter::NONE to skip the output of the date
• IntlDateFormatter::FULL with weekday
• IntlDateFormatter::LONG
• IntlDateFormatter::MEDIUM
• IntlDateFormatter::SHORT

time type argument

If NULL, it will select IntlDateFormatter::FULL.

• IntlDateFormatter::NONE to skip the output of the time
• IntlDateFormatter::FULL with time zone description
• IntlDateFormatter::LONG
• IntlDateFormatter::MEDIUM
• IntlDateFormatter::SHORT

time zone argument

• https://www.php.net/manual/en/function.date-default-timezone-get.php

If NULL, it will lookup its default value in this order:

1. date_default_timezone_get()
2. ini_get('date.timezone')
3. 'UTC'

calendar argument

• https://www.php.net/manual/en/class.intlcalendar.php

If NULL, it will select IntlDateFormatter::GREGORIAN.

pattern argument

• https://unicode-org.github.io/icu/userguide/format_parse/datetime

If not NULL, it will override date type and time type arguments.
If NULL, it will defer to date type and time type arguments.