Executing this API call. Sending json as parameter?

I am working with API called "Active Collab", I am trying to build a custom report.

API::get('/users/3/time-records/filtered-by-date')

Query Parameters:
{
    "from": "2014-12-01",
    "to": "2014-12-31"
}

I don't know how to do this...

I tried API::get('/users/3/time-records/'.$filtered-by-date)

$filter-by-date = {
        "from": "2014-12-01",
        "to": "2014-12-31"
    }

and

$filter-by-date = json_encode({
        "from": "2014-12-01",
        "to": "2014-12-31"
    });

it just never works.. I must be doing the filter-by-date wrong, however I just don't know what to do here.

Thanks

EDITED:

Tried this as well

$filter_by_date = json_encode(["from"=>"2014-12-01","to"=> "2014-12-31"]);

API::get('/users/'.$request->get('employee').'/time-records/filter_by_date')

Still nothing..

Top of my post is how API doc shows it I just have no idea how to execute that...