pikaday angular sending json format

how do i send json date format using pikaday angular plugin using ng-model.

i have been trying this

{{product.product_name}}
{{products_chosen[$index]}} {{myPickerObject}}

js:

    $scope.products_chosen = [{"from":new Date(),"till":new Date(),"checkbox":0}];
    $scope.productChange = function(index, checkbox){
        if(checkbox==1){
            $scope.products_chosen.push({"from":"","till":"","checkbox":0});  
        }
        else{
            $scope.products_chosen.splice(index,1);
        } 
    }