ng-model is not changing when choosing a date

[farzaneHashemi]

Hi,
I have a strange problem which I can't have my ng-model variable changing when I choose a date on my calendar.
here is my code:
controller:
$scope.to1 = new Date();
$scope.ww = function () { console.log('to1', $scope.to1) }

html:
<adm-dtp ng-model="to1" on-close="ww()"></adm-dtp>

I keep getting today's date in console whether I choose today or any other date.