« DateTimeImmutable::setTimezone DateTimeInterface » PHP Manual DateTimeImmutable Subtracts an amount of days, months, years, hours, minutes and seconds DateTimeImmutable::sub (PHP 5 >= 5.5.0, PHP 7) DateTimeImmutable::sub — Subtracts an amount of days, months, years, hours, minutes and seconds 说明 public DateTimeImmutable::sub ( DateInterval $interval ) : DateTimeImmutable Like DateTime::sub() but works with DateTimeImmutable.