<div class="{{data}}">

    <div class="time" ng-class="{'invisible': data.level < 0}">{{data.timestamp | date: 'ha'}}</div>
    <div class="bar">
        <ul class="slots">
           <li class="{{slot.type}}" ng-repeat="slot in slots"></li>
       </ul>
    </div>
    <div class="time" ng-class="{'invisible': data.level >= 0}">{{data.timestamp | date: 'ha'}}</div>
</div>