curl --request PUT \
  --url https://api.hubapi.com/crm/lists/2026-03/{listId}/schedule-conversion \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "conversionType": "CONVERSION_DATE",
  "day": 123,
  "month": 123,
  "year": 123
}
'

{
  "listId": "<string>",
  "convertedAt": "2023-11-07T05:31:56Z",
  "requestedConversionTime": {
    "conversionType": "CONVERSION_DATE",
    "day": 123,
    "month": 123,
    "year": 123
  }
}