IntlCalendar::roll

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

IntlCalendar::roll — Add value to field without carrying into more significant fields

Description

Object-oriented style

public IntlCalendar::roll(int $field, int|bool $value): bool

Procedural style

intlcal_roll(IntlCalendar $calendar, int $field, int|bool $value): bool

Adds a (signed) amount to a field. The difference with respect to IntlCalendar::add() is that when the field value overflows, it does not carry into more significant fields.

Parameters

calendar

An IntlCalendar instance.

field

One of the IntlCalendar date/time field constants. These are integer values between 0 and IntlCalendar::FIELD_COUNT.

value

The (signed) amount to add to the field, true for rolling up (adding 1), or false for rolling down (subtracting 1).

Return Values

Returns true on success or false on failure.

Examples

Example #1 IntlCalendar::roll()

<?php
ini_set('date.timezone', 'Europe/Lisbon');
ini_set('intl.default_locale', 'pt_PT');

$cal = new IntlGregorianCalendar(2013, 5 /* June */, 30);

$cal->add(IntlCalendar::FIELD_DAY_OF_MONTH, 1);
var_dump(IntlDateFormatter::formatObject($cal)); // "01/07/2013, 00:00:00"

$cal->set(2013, 5 /* June */, 30);
$cal->roll(IntlCalendar::FIELD_DAY_OF_MONTH, true); // roll up, same as rolling +1
var_dump(IntlDateFormatter::formatObject($cal)); // "01/06/2013, 00:00:00"

The above example will output:

string(20) "01/07/2013, 00:00:00"
string(20) "01/06/2013, 00:00:00"

See Also