Partners can now update room rates for shoulder dates via PUT /groups/{id}/room_rates, in addition to core group stay dates. Shoulder date rate updates are supported for existing groups only and are not available during group creation, consistent with PMS behaviour. Submitting dates outside both the core group stay and shoulder window returns HTTP 422.

Example request:

{
  "room_rates": [
    {
      "from_date": "2025-07-01",
      "to_date": "2025-07-02",
      "room_type_id": 1452,
      "single": "170.00",
      "double": "190.00",
      "extra_adult_amount": "95.00"
    }
  ]
}