Breaking: #96550 - TYPO3_CONF_VARS[‘SYS’][‘USdateFormat’] removed

See Issue #96550

Description

The TYPO3 configuration had a boolean toggle $GLOBALS['TYPO3_CONF_VARS']['SYS']['USdateFormat'] that changed the date rendering from “day-month-year” to “month-day-year” in a couple of places in the backend - most prominently when editing records.

This configuration conflicts with option $GLOBALS['TYPO3_CONF_VARS']['SYS']['ddmmyy'], which is a broader approach to configure a system wide date rendering format, especially in combination with option $GLOBALS['TYPO3_CONF_VARS']['SYS']['hhmm'].

To streamline date and time rendering in the backend and to eventually implement a user-based and timezone-aware solution, option USdateFormat has been removed in favor of ddmmyy from the configuration and is ignored now.

Impact

Backend users of instances with this option set to true will experience swapped day and month rendering when editing records in the backend.

The option is removed automatically from LocalConfiguration.php when upgrading to TYPO3 v12.

Affected Installations

Instances having $GLOBALS['TYPO3_CONF_VARS']['SYS']['USdateFormat'] set to default false see no difference and are not affected. Instances with this option set to true are affected.

The extension scanner will find matching candidates in case the option is used in extensions.

Migration

Extensions accessing $GLOBALS['TYPO3_CONF_VARS']['SYS']['USdateFormat'] should assume false to keep compatibility with previous TYPO3 versions, and should phase out the option usage.