Contao Date Display Shows Wrong Time Zone on Multilingual Site

Goal

Ensure that dates rendered in a Contao CMS site appear in the correct regional time zone for each language, while keeping the core configuration stable.

Constraints & Uncertainty

• Contao uses the PHP date.timezone setting for its default system offset.
• Dates are formatted in Twig via the date filter, which relies on PHP’s DateTime objects.
• There is no native per‑user or per‑language time‑zone configuration in the core admin panel.
• Global caching or CDN delivery may interfere with on‑the‑fly time‑zone conversion.

Questions

1. Does Contao store all timestamps in UTC or in the server’s configured time zone?
2. What mechanisms exist to override the time zone for a specific language or user session within Twig templates?
3. How does CDN caching affect the time‑zone conversion performed by Contao, and what strategies can mitigate potential inconsistencies?