I'm trying to add a date value to a date field in an isheet.

I'm using the /3/isheet/{isheetid}/items/{itemid} REST API call, and am passing the iSheet column values in a payload object.

I am able to write to text fields, but I can't seem to write to date fields.  I checked the iSheet and the date field I'm trying to update is date only, with a MM/DD/YYYY date format.  In the payload, I'm populating:

{
  "recordcount": "1",
  "data": {
    "item": [
      {
        "itemid": "15962",
        "column": [
          {
            "rawdata": {
              "value": "01/01/2020",
              "date": "01/01/2020",
              "time": "00:00:00",
              "choices": null

            },
            "attributecolumnid": 9459
          }
       

Any idea what I'm doing wrong?