GraphQL aggregate query not working for an array of DateTimes

Hi, I have a type in my GraphQL schema that looks like the following:

type Event {
	id: ID! 
	label: String
	updateTS: DateTime
	date: [DateTime]
}

According to the docs at https://dgraph.io/docs/graphql/queries/aggregate/#advanced-aggregate-queries-for-child-nodes , I would expect the schema to generate Min and Max fields for label, updateTS and date ("This is done for each field that is of type List[Type/Interface] ").

However I only get the aggregate fields for label and updateTS, not date. I guess this is because date is a List and an not an actual child node? Is this by design or a bug?

Thanks,
Rob