Wrong date for "Jeûne Fédéral" in Switzerland 2026

The date for the "Jeûne Féréral" or "Lundi du jeûne" should always be a monday. For 2026, it is registered to be a Sunday (2026-09-20). It should be on 2026-09-21.

```
    "id": "cddd771c-afd2-46b8-9e8b-4753d471357f",
    "startDate": "2026-09-20",
    "endDate": "2026-09-20",
    "type": "Public",
    "name": [
      {
        "language": "FR",
        "text": "Jeûne fédéral"
      }
    ],
```