Set the day on which the week is deemed to start

# IntlCalendar::setFirstDayOfWeek

(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)

IntlCalendar::setFirstDayOfWeek — Set the day on which the week is deemed to start

### Description

Object-oriented style

public IntlCalendar::setFirstDayOfWeek(int `$dayOfWeek`): true

Procedural style

intlcal_set_first_day_of_week(IntlCalendar `$calendar`, int `$dayOfWeek`): true

Defines the day of week deemed to start the week. This affects the behavior of fields that depend on the concept of week start and end such as `IntlCalendar::FIELD_WEEK_OF_YEAR` and `IntlCalendar::FIELD_YEAR_WOY`.

### Parameters

`calendar`

  An IntlCalendar instance.

`dayOfWeek`

  One of the constants `IntlCalendar::DOW_SUNDAY`, `IntlCalendar::DOW_MONDAY`, …, `IntlCalendar::DOW_SATURDAY`.

### Return Values

Always returns `true`.

### Changelog

Version | Description
--- | ---
8.2.0 | The return type is `true` now; previously, it was bool.

### Examples

Example #1 IntlCalendar::setFirstDayOfWeek()

`<?php
ini_set('date.timezone', 'Europe/Lisbon');
ini_set('intl.default_locale', 'es_ES');
$cal = IntlCalendar::createInstance();
$cal->set(2013, 5 /* June */, 30); // A Sunday
var_dump($cal->getFirstDayOfWeek()); // 2 (Monday)
echo IntlDateFormatter::formatObject($cal, <<<EOD
'local day of week: 'cc'
week of month : 'W'
week of year : 'ww
EOD
), "\n";
$cal->setFirstDayOfWeek(IntlCalendar::DOW_SUNDAY);
echo IntlDateFormatter::formatObject($cal, <<<EOD
'local day of week: 'cc'
week of month : 'W'
week of year : 'ww
EOD
), "\n";`

The above example will output:

    int(2)
    local day of week: 7
    week of month    : 4
    week of year     : 26
    local day of week: 1
    week of month    : 5
    week of year     : 27

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