角度 UI 日历事件消失

>我正在使用角度UI日历填充数据库中的事件。 例如，我有一些 12 月（当前月份）的事件，当我的日历加载时，它会正确显示事件，但是当我从 12 月导航到 1 月并返回时，我的事件消失了，我在日历上看不到任何事件。我想知道为什么。请帮忙:) 这是我的日历控制器

app.controller('CalendarController', function ($scope,$compile,uiCalendarConfig,learnerService) {
    var date = new Date();
    var d = date.getDate();
    var m = date.getMonth();
    var y = date.getFullYear();
    $scope.events = [];
var promise = learnerService.getBirthdays();
promise.then(function(data){
for (var i = 0; i < data.length; i++) {
  $scope.events.push({title:data[i].learner_name, start: new Date(data[i].birthday)});
};

});

    /* event source that contains custom events on the scope */

    /* event source that calls a function on every view switch */
    $scope.eventsF = function (start, end, timezone, callback) {
      var s = new Date(start).getTime() / 1000;
      var e = new Date(end).getTime() / 1000;
      var m = new Date(start).getMonth();
      var events = [{title: 'Feed Me ' + m,start: s + (50000),end: s + (100000),allDay: false, className: ['customFeed']}];
      callback(events);
    };
    $scope.calEventsExt = {
       color: '#000000',
       textColor: 'yellow',
       events: [ 
          {type:'party',title: 'Lunch',start: new Date(y, m, d, 12, 0),end: new Date(y, m, d, 14, 0),allDay: false},
          {type:'party',title: 'Lunch 2',start: new Date(y, m, d, 12, 0),end: new Date(y, m, d, 14, 0),allDay: false},
          {type:'party',title: 'Click for Google',start: new Date(y, m, 28),end: new Date(y, m, 29),url: 'http://google.com/'}
        ]
    };
    /* alert on eventClick */
    $scope.alertOnEventClick = function( date, jsEvent, view){
        $scope.alertMessage = (date.title + ' was clicked ');
    };
    /* alert on Drop */
     $scope.alertOnDrop = function(event, delta, revertFunc, jsEvent, ui, view){
       $scope.alertMessage = ('Event Droped to make dayDelta ' + delta);
    };
    /* alert on Resize */
    $scope.alertOnResize = function(event, delta, revertFunc, jsEvent, ui, view ){
       $scope.alertMessage = ('Event Resized to make dayDelta ' + delta);
    };
    /* add and removes an event source of choice */
    $scope.addRemoveEventSource = function(sources,source) {
      var canAdd = 0;
      angular.forEach(sources,function(value, key){
        if(sources[key] === source){
          sources.splice(key,1);
          canAdd = 1;
        }
      });
      if(canAdd === 0){
        sources.push(source);
      }
    };
    /* add custom event*/
    $scope.addEvent = function() {
      $scope.events.push({
        title: 'Open Sesame',
        start: new Date(y, m, 28),
        end: new Date(y, m, 29),
        className: ['openSesame']
      });
    };
    /* remove event */
    $scope.remove = function(index) {
      $scope.events.splice(index,1);
    };
    /* Change View */
    $scope.changeView = function(view,calendar) {
      uiCalendarConfig.calendars[calendar].fullCalendar('changeView',view);
    };
    /* Change View */
    $scope.renderCalender = function(calendar) {
      if(uiCalendarConfig.calendars[calendar]){
        uiCalendarConfig.calendars[calendar].fullCalendar('render');
      }
    };
     /* Render Tooltip */
    $scope.eventRender = function( event, element, view ) { 
        element.attr({'tooltip': event.title,
                     'tooltip-append-to-body': true});
        // $compile(element)($scope);
    };
    /* config object */
    $scope.uiConfig = {
      calendar:{
        height: 450,
        editable: true,
        header:{
          left: 'title',
          center: '',
          right: 'today prev,next'
        },
        eventClick: $scope.alertOnEventClick,
        eventDrop: $scope.alertOnDrop,
        eventResize: $scope.alertOnResize,
        eventRender: $scope.eventRender
      }
    };
    $scope.changeLang = function() {
      if($scope.changeTo === 'Hungarian'){
        $scope.uiConfig.calendar.dayNames = ["Vasárnap", "Hétfő", "Kedd", "Szerda", "Csütörtök", "Péntek", "Szombat"];
        $scope.uiConfig.calendar.dayNamesShort = ["Vas", "Hét", "Kedd", "Sze", "Csüt", "Pén", "Szo"];
        $scope.changeTo= 'English';
      } else {
        $scope.uiConfig.calendar.dayNames = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
        $scope.uiConfig.calendar.dayNamesShort = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
        $scope.changeTo = 'Hungarian';
      }
    };