CQL Mutation Query Passing Json Parameter

Question

I have a GraphQL API connected to a Cassandra database.

Here's my mutation Query to retrieve acc and name fields from the table based on date:

query($date: String) {
   getResources(date: $date ) {
    list {
        acc
        name
    }
    }
}

Sample Query:

query{getResourcesInput(getResources:{date:{eq:"2020-06-28T16:48:37.000+0000"}}){
list {
        acc
        name
    }
    }
}

What CQL data type should I set for the date field? It expects a json object. Here's the error I get when set to String.

{"errors":[{"error_code":"400-901","description":"Validation error of type FieldUndefined","field_name":"getResources"}]}