Web Api 2 - custom data type JSON serialization

I'm actually new to Web Api, so my question may sound a bit odd.

I have simple API to return historical information about price changes. My controller's action looks like this:

[HttpGet]
[Route("api/history/{id}/{size}")]
public async Task<IEnumerable<PriceHistoryRecordModel>> GetHistory(string id, Size size)

where PriceHistoryRecordModel is

[DataContract]
public class PriceHistoryRecordModel
{
    [DataMember]
    public DateTime Date { get; set; }

    [DataMember]
    public double Value { get; set; }
}

However, the problem is - action returns JSON in following format

[{"Date":"2016-02-07T08:22:46.212Z","Value":17.48},{"Date":"2016-02-08T09:34:01.212Z","Value":18.37}]

but, due to specific client requirements to data format, I need my JSON to look this way

[[1238371200000,17.48],[1238457600000,18.37]]

So, I wonder

• if there's a way to achieve such custom serialization?
• can I wrap this custom serialization in an attribute and use it as an aspect?