What is the format you’re trying to pass in? The form on a website can probably take in a ‘pretty’ date and format it automatically. But if you’re trying to pass in a ‘pretty’ date in through the API, it will likely interpret it as a list or text. It has to be in one of the supported formats:

• https://developers.klaviyo.com/en/docs/acceptable_date_and_timestamp_formats_for_profile_and_event_properties

I’ve tried every one of those formats with no success.

Here is the current payload and what I get back.

{
  "data": {
    "type": "profile",
    "id": "XXXXXXXXX",
    "attributes": {
    },
    "properties": {
      "LapsedDate": "2024-10-04T00:00:00Z"
    },
    "meta": {
      "patch_properties": {
        "append": {
          "LapsedDate": "2024-10-04T00:00:00Z"
        }
      }
    }
  }
}

"properties": {
  "MailChimp Rating": 2,
  "LapsedDate": :
    "2024-10-04T00:00:00Z"
  ]
}

Another dumb question, have you verified in the profile page or segment builder that it’s *not* being treated as a date after sending it in via API?

Yes I have confirmed that. If I put the date in manually it segments correctly. If I put the date in via API it is treated as text for the segmenting. 

Manually it looks like 2024-10-04T00:00:00Z

API it looks like e“2024-10-04T00:00:00Z”]

If I take out the brackets and quotes manually from the api entered data it is treated like a date.