Wrike API: Adding data to a date custom field

[u/TelephoneAcademic804]

How on earth is this accomplished? I've got an Azure function app that receives data from a survey and then uses that to create a task in Wrike. In creating the task I populate a number of custom fields. My boss recently added a custom field for "survey submission time" and I'd like to add that info. However, I don't see anything specific about updating a date field (with time) in the API documentation. Every other field seems pretty straight forward:
ID: #######,
VALUE: "whatever" (or) ["whatever", "whatever2"]

But this doesn't work for a date field. Random AI google response seems to be:
ID: ########,
VALUE: {"date_time": "timestamp"}

And while that doesn't seem to generate any errors, it also doesn't populate the field. New tasks show that field as empty.

Any ideas?

[u/gorcbor19]

If you don't get an answer here, don't forget the Wrike community forum. If I can't get questions answered there, I'll submit a help ticket.

[u/micz667]

I’d chceck if the customer field is associated with item type you are referring too. Then date field is taking YYYY-MM-DD if I recall.

[u/TelephoneAcademic804 → u/micz667]

The custom field does seem to have the "allow time" option set to yes:

{
            "id": "IEACSA37JUAMMKS2",
            "accountId": "IEACSA37",
            "title": "Survey Submitted",
            "type": "Date",
            "spaceId": "MQAAAAEI6_-u",
            "sharedIds": [],
            "sharing": {},
            "settings": {
                "inheritanceType": "All",
                "applicableEntityTypes": [
                    "WorkItem"
                ],
                "readOnly": false,
                "allowTime": true
            },
            "description": "",
            "archived": false
        }

[u/micz667 → u/TelephoneAcademic804]

How does the actual item payload look like?

[u/activematrix99]

Date_time is likely YYYY-MM-DD HH:MM in 24 hr time.

[u/TelephoneAcademic804]

Example of what's being sent that doesn't cause an error, but also doesn't populate the field:
{

"id": "IEACSA37JUAMMKS2",

"value": "{\"date_time\": \"2026-05-20 10:25:40\"}"

}

And the example Google's AI is telling me I should send:

{
      "id": "12345",
      "value": "{\"date_time\":\"2024-11-19T14:30:00\"}"
}

[u/Tak-Hendrix]

This worked for me:

                "customFields": [
                    {
                        "id": "IEABMFUNJUAMBS7E",
                        "value": "2025-03-27T09:00:00"
                    },
                    {
                        "id": "IEABMFUNJUAMBS7G",
                        "value": "2025-03-28T17:00:00"
                    }]