If you select a different date format on the computer, other than English, in the game, the date format will not change. In version 1.10.2 and earlier all worked fine.
Steps to Reproduce
1. Just change the date format on your computer, for example, DD.MM.YYYY.
2. Restart Minecraft.
3. Click "Single player".
4. If you already have any world view at the date and time, or create a new world, exit it and look at the date.
Thank you for your report!
However, this issue has been closed as a Duplicate of MC-5820.
It has been linked to this report. If you have additional information, please add it to that report.
Please search before reporting, as it's likely that one exists already.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki