curl -X PUT "https://api.nevatal.com/api/v1/appointments/apt_xyz789" \
  -H "Authorization: Bearer nvtl_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "startTime": "2025-04-02T10:00:00-05:00",
    "endTime": "2025-04-02T10:30:00-05:00"
  }'

{
  "id": "apt_xyz789",
  "startTime": "2025-04-02T10:00:00-05:00",
  "endTime": "2025-04-02T10:30:00-05:00",
  "status": "confirmed",
  "updatedAt": "2025-03-21T08:00:00Z"
}