dynamic elements added to scope does not validate

[codeplaygoa]

i have a form which has ng-repeat for scope variable timings_edit

<form  method="post" name="Form" >
				<div class="timing-set" add-timings>
					<div class="time-slot-block col-md-12" ng-repeat="(key,value) in timings_edit">
						<div class="available-days new-day">
							<ul>
								<span>Availability</span>
								<li ng-repeat="dayname in weekdays" >
									<label for="checklabel" class="days">
										<input class="checkbox-custom" type="checkbox" ng-model="timings_edit[key]['days'][dayname].checked" ng-checked="timings_edit[key]['days'].hasOwnProperty(dayname)" >
										<label class="checkbox-custom-label"></label>
										{{dayname}}											
									</label>																			
								</li>								
							</ul>
						</div>
						<div class="available-times new-time">
							<p class="input_label_container" ng-class="{'move-label':timings_edit[key].time_from!=''}">
								<input type="text" class="input-text timepic" ng-model="timings_edit[key].time_from" add-timepicker validator="required" >
								<span class="floating-label">From</span>
							</p>
							<p class="input_label_container" ng-class="{'move-label':timings_edit[key].time_to!=''}">
								<input type="text" class="input-text timepic" ng-model="timings_edit[key].time_to" add-timepicker  validator="required">
								<span class="floating-label">To</span>
							</p>
						</div>
						<div class="actions">
							<div id="timing-set_{{key}}" class="delete-notification hide">
								<p>Are you Sure ? </p> 
								<i class="icon icon-rounded-white icon-check" ng-click="delete_timings(timings_edit[key], $index)"></i>
								<i class="icon icon-rounded-white icon-delete-white" ng-click="remove_notification($event,'delete-notification');" ></i>
							</div>
							<div class="delete-time icon icon-rounded icon-delete" ng-click="prompt_notification($event,'delete-notification');"></div>
						</div>
					</div>
				</div>
				<div class="add-btn">
					<div class="add-more-time btn" ng-click="add_timing();">
						<a>Add new Time slot</a>
					</div>
					<input type="submit" validation-submit="Form" class="btn dark-btn" ng-click="save_timings();" value="Save timing set" />
				</div>
			</form>	

when i click the add new time slot it pushes an empty object to the scope element

$scope.add_timing = function(){
		$scope.$watch('ng-model', function(newval) {
			var blank = {'time_from':'','time_to':'','days':{}};
			$scope.timings_edit.push(blank);
		});
	}

on clicking save timing set it does not validate the newly added elements
throws angular-combine.js:122 Possibly unhandled rejection: error

[hueitan]

maybe you want to simplify the code or showing us a demo link? for us easier to track what's the problem.