How to enforce ordering within nested objects?

[pure]

I'm using elasticsearch as a Key-Value store, so that I can guarantee the query always return just 1 document. There is a nested field in the document schema, and I want to make sure multiple values within the nested object are returned in order.

More concretely, I have

{
    "mappings": {
        "properties": {
            "neighborhood": {
                "type": "keyword"
            },
            "forecast": {
                "type": "nested",
                "properties": {
                    "date": {
                        "type": "date"
                    },
                    "demand": {
                        "type": "double"
                    }
                }
            }
        }
    }
}

my base query looks like this:

{
    "query": {
        "bool": {
            "must": [
                {
                    "term": {
                        "neighborhood": "Hogwarts"
                    }
                }
            ]
        }
    }
}

and I got back result with randomly ordered forecast objects not sorted by date

"_source": {
                    "neighborhood": "Hogwarts",
                    "forecast": [
                        {
                            "date": 3,
                            "demand": 4.895964622497559
                        },
                        {
                            "date": 1,
                            "demand": 5.326427459716797
                        },
                        {
                            "date": 2,
                            "demand": 5.326427459716797
                        }
}

How do i modify the query so that it can return document where within the forecast object it is sorted by date.

I found many examples which explained how to sort the multiple parent documents based on nested objects fields, but I haven't seen an example explaining how to enforce ordering of values within nested objects itself.

Thanks!