AWS::IoTAnalytics::Dataset creation throws InvalidRequestException

I've been trying to create an IoTAnalytics Dataset through CloudFormation, but it's throwing multiple strange errors.

At first I tried to create a Dataset with no RetentionPeriod, but this resulted in the following error:

Property validation failure: [The property {/RetentionPeriod/NumberOfDays} is required]

This is rather strange because I had configured the retention with

"Unlimited": true

Creating the Dataset without RetentionPeriod throws the following 400 exception: Invalid value of namespace's value : scheduledTime (Service: AWSIoTAnalytics; Status Code: 400; Error Code: InvalidRequestException; Request ID: e9e8b946-62cb-46ca-86fa-55c393ddf4f9) I can't find any CF reference to a property named "scheduledTime". Am I doing something wrong?

The redacted template I was trying to use is:

{
    "Type": "AWS::IoTAnalytics::Dataset",
    "Properties": {
        "DatasetName": "********",
        "Actions": [
            {
                "ActionName": "********",
                "QueryAction": {
                    "SqlQuery": "<secret>"
                }
            }
        ],
        "ContentDeliveryRules": [
            {
                "Destination": {
                    "S3DestinationConfiguration": {
                        "Bucket": {
                            "Ref": "OutputBucket"
                        },
                        "Key": "/********/!{iotanalytics:scheduledTime}/!{iotanalytics:versioned}.csv",
                        "RoleArn": {
                            "Fn::GetAtt": [
                                "IoTAnalyticsRole",
                                "Arn"
                            ]
                        }
                    }
                }
            }
        ],
        "Tags": [
            {
                "Key": "CostAlloc",
                "Value": "********"
            }
        ]
    },
    "Metadata": {
        "AWS::CloudFormation::Designer": {
            "id": "90f1a6df-655e-476a-90e9-148a3079fa23"
        }
    }
}