Is there anyway to query off a certain date in the rally web api?

I can do the comparison after the fact, but I know it would be more effecient to filter out the data at the initial query. Is there a way to do something similar to

queryConfig[1] = {



        type : 'iteration',

        key  : 'iterations',

        query: 'StartDate > new Date() ',

        fetch: 'Name,TaskEstimateTotal,Resources'

};