DateTimeImmutable
PHP Manual

DateTimeImmutable::add

(PHP 5 >= 5.5.0)

DateTimeImmutable::add Adds an amount of days, months, years, hours, minutes and seconds

说明

public DateTimeImmutable DateTimeImmutable::add ( DateInterval $interval )

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


DateTimeImmutable
PHP Manual