How to make Date picker ‘maxdate’ based on another datepicker

 angular.module('plunker', ['ngAnimate', 'ui.bootstrap']);
        angular.module('plunker').controller('fromDateCtrl', function ($scope) {
            $scope.today = function () {
                $scope.model1 = new Date();
            };
            $scope.mindate = new Date();
            $scope.dateformat="MM/dd/yyyy";
            $scope.today();
            $scope.showcalendar = function ($event) {
                $scope.showdp = true;
            };
            $scope.showdp = false;
        });

        angular.module('plunker').controller('toDateCtrl', function ($scope) {
            $scope.today = function () {
                $scope.model2 = new Date();
            };
            $scope.mindate = new Date();
            $scope.dateformat="MM/dd/yyyy";
            $scope.today();
            $scope.showcalendar = function ($event) {
                $scope.showdp = true;
            };
            $scope.showdp = false;
        });