Unable to update a Summary field of type DATE using the C# SDK

Hi Smartsheet Community!

This is my first post and I hope not to scare you away.

I've been finding the community amazingly helpful in everything I've been doing so far. Now I'm blocked and I hope someone can give me a hand .

I'm trying to set a Summary field "Project Due Date" across multiple sheets.This Summary field is of type DATE.

It works fine when I try it via the REST API in Postman.

This is the request:

PUT https://api.smartsheet.com/2.0/sheets/{sheetId}/summary/fields

This is the request body, where the ID belongs to a summary field of type DATE: 

[

    {        

            "id": {summaryFieldId},

                   "objectValue": {

                       "objectType": "DATE",

                       "value": "2019-11-20"

                   }

    }

]

This works perfectly fine: the summary field gets updated to the value "11/20/19" in my UI (see attached image).

Now, when I try to do this through the API using the C# SDK, the program runs smoothly but the summary field remains empty.

Below is the code. I cannot figure out what I'm doing wrong. Your help is much appreciated!

SummaryField fieldToUpdate = new SummaryField();

fieldToUpdate.Id = {summaryFieldId};

fieldToUpdate.ObjectValue = new DateObjectValue(ObjectValueType.DATE, "2019-11-20");

List<SummaryField> updateSummaryFields = new List<SummaryField>();

updateSummaryFields.Add(fieldToUpdate);

IList<BulkItemFailure> failedResults = new List<BulkItemFailure>();

failedResults = smartsheet.SheetResources.SummaryResources.UpdateSheetSummaryFieldsAllowPartialSuccess({sheetId}, updateSummaryFields, false).FailedItems;

 

Note:

It works fine with summary fields of type TEXT_NUMBER, where I'm using the following code:

fieldToUpdate.ObjectValue = new StringObjectValue("a string");

Regards

Helena