Starting date dont work with angular

I'm using materialize that use pickdate.js in its framework.
I'm also using angularjs in a website. So I've an input fields to change birthday:

input type="date" class="datepicker" ng-model="profilo.nascita"

My problem is that if I set my birthday, for example, on 24-02-1977 when I open datepicker, start from today! If I change date from picker, set, and then re-open, the picker start from the last selected date!

Is it an angular problem?!