Временные зоны

$datePeriodfrom = new DateTime();
$datePeriodfrom->setTimestamp($timestamp);
$datePeriodfrom->setTimezone(new DateTimeZone($fromTimezone)); //"Asia/Yekaterinburg"
$dateStart = $datePeriodfrom->format(DateTime::ISO8601);

Logger::writeLog($dateStart);
Logger::writeLog($fromTimezone);
Logger::writeLog(date('H:i',strtotime($dateStart)));

echo (new DateTime($dateStart, new DateTimeZone($fromTimezone)))->format(DateTime::ISO8601);

<?php
$datePeriodfrom = new DateTime();
 
$fromTimezone = "Asia/Yekaterinburg";
$datePeriodfrom->setTimeZone(new DateTimeZone($fromTimezone)); //"Asia/Yekaterinburg"
 
$dateStart = $datePeriodfrom->format(DateTime::ISO8601);
 
echo $dateStart, PHP_EOL;
echo $fromTimezone, PHP_EOL;
$dt = new DateTime($dateStart, new DateTimeZone($fromTimezone));
echo $dt->format('H:i');
/*
2025-05-25T01:13:06+0500
Asia/Yekaterinburg
01:13
*/