ds-site/Configuration/TCA/Overrides/pages.php

<?php

(function (string $extensionKey, string $tableName) {
    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::registerPageTSConfigFile(
        $extensionKey,
        'Configuration/PageTSconfig/Index.tsconfig',
        $extensionKey
    );

    \TYPO3\CMS\Core\Utility\ArrayUtility::mergeRecursiveWithOverrule($GLOBALS['TCA'][$tableName], [
        'columns' => [
            'lastUpdated' => [
                'config' => [
                    'eval' => 'date,int',
                ],
            ],
        ],
    ]);
})('ds_site', 'pages');