DateTimeImmutable::add

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

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

说明

public DateTimeImmutable::add ( DateInterval $interval ) : DateTimeImmutable

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

User Contributed Notes

Gunnar Bernstein 12-Dec-2018 11:00


Please note, add() works a litte different than for DateTime-Objects.



Since DateTimeImmutable is in fact immutable. A line like this will not work:



    $di = new DateTimeImmutable("2018-12-12T10:00:00");

    $di->add(new DateInterval('PT45M')); // $di unchanged !!!



compared to



    $dt = new DateTime("2018-12-12T10:00:00");

    $dt->add(new DateInterval('PT45M')); // added 45 minutes



so you need to write



    $di = new DateTimeImmutable("2018-12-12T10:00:00");

    $di = $di->add(new DateInterval('PT45M')); // $di now changed