Laravel date_format, timezones, DST and validation - php

Question

I'm trying to validate a date in a request to a controller in Laravel.
Basically I want to validate the date 2023-03-26T02:15:00.000Z. This date and time without the Z does not exist in my timezone (Europe/Zurich) because of DST. But since there's a Z at the end, I expect Laravel to "get" it and check in the right timezone.
I'm not sure it's a PHP bug, maybe more that I'm not doing it right. Any idea how I could achieve my goal?
Laravel request validation rules:
public function rules()
{
return [
'date' => 'nullable|date_format:Y-m-d\TH:i:s.v\Z',
];
}
Smallest code to reproduce:
<?php
// All 3 dates should be the same
date_default_timezone_set('Europe/Zurich');
// Laravel config/app.php:
// 'timezone' => 'Europe/Zurich',
$date = "2023-03-26T02:15:00.000Z";
$format = "Y-m-d\\TH:i:s.v\\Z";
echo $date . "\n"; // 2023-03-26T02:15:00.000Z
// What I should do
$d1 = DateTime::createFromFormat($format, $date, new DateTimeZone('UTC'));
echo $d1->format($format) . "\n"; // 2023-03-26T02:15:00.000Z
// What Laravel does
$d2 = DateTime::createFromFormat($format, $date);
echo $d2->format($format) . "\n"; // 2023-03-26T03:15:00.000Z
// which results in an invalid date because it's not the same as $date
So how can I tell Laravel to validate the date in the UTC timezone?

Answer 1

The following format should accept your date:
$date = \DateTime::createFromFormat('Y-m-d\TH:i:s.uP', '2023-03-26T02:15:00.000Z');
You can also use lowercase p, see the difference here: https://www.php.net/manual/en/datetime.format.php
This is basically an edit for \DateTimeInterface::ATOM = 'Y-m-d\TH:i:sP' which does not accept microtime by default.
Your setting of date_default_timezone_set(...) or config/app.php::timezone should not matter in this case since your date specifically passes "Z" which is UTC+0. However leaving out the P from the required format AND your input will default to your given timezone.