MergeDateTimePropertyTypeDeclarationRector

Set DateTime to DateTimeInterface for DateTime property with DateTimeInterface docblock

 final class SomeClass
 {
-    /**
-     * @var DateTimeInterface
-     */
-    private DateTime $dateTime;
+    private DateTimeInterface $dateTime;
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\TypeDeclaration\Rector\Class_\MergeDateTimePropertyTypeDeclarationRector;

return RectorConfig::configure()
    ->withRules([
        MergeDateTimePropertyTypeDeclarationRector::class,
    ]);