DateTimeImmutable
PHP Manual

DateTimeImmutable::setISODate

(PHP 5 >= 5.5.0, PHP 7)

DateTimeImmutable::setISODateSets the ISO date

说明

public DateTimeImmutable DateTimeImmutable::setISODate ( int $year , int $week [, int $day = 1 ] )

Like DateTime::setISODate() but works with DateTimeImmutable.


DateTimeImmutable
PHP Manual