Google Analytics connector missing startdate/enddate parameters

[intrasight]

I thought this had been asked before, but I didn't find a thread via search.

A GA connection has a query pattern like so:

let
    Source = GoogleAnalytics.Accounts(),
    account = Source{[Id="654321"]}[Data],
    webprop = account{[Id="UA-654321-1"]}[Data],
    profile = webprop{[Id="123456"]}[Data],
    gadata = Cube.Transform(
        profile,
        {
           {
              Cube.AddAndExpandDimensionColumn, 
              "ga:date", 
              {"ga:date"}, 
              {"Date"}
           }, 
           {
              Cube.AddMeasureColumn, 
              "Sessions", 
              "ga:sessions"
           }
        }
    ),
in
  gadata

That seems to provide coverage for the GA API except for the start date and end date parameters. Are those parameters exposed in some way? If not, how does one specify a query like "users last month".  Would it be possible to add them as optional parameters to the GoogleAnalytics.Accounts() or Cube.Transform() function?