<script type="text/javascript">
LoadSodByKey("SP.UI.ApplicationPages.Calendar.js", function () {
        WaitForCalendarToLoad();
    });
var SEPARATOR = "|||";
  
function WaitForCalendarToLoad() {
        SP.UI.ApplicationPages.SummaryCalendarView.prototype.renderGrids = function SP_UI_ApplicationPages_SummaryCalendarView$renderGrids($p0) {
        var $v_0 = new Sys.StringBuilder();
        var $v_1 = $p0.length;        for (var $v_2 = 0; $v_2 < $v_1; $v_2++) {
            this.$7V_2($v_2, $p0[$v_2]);
        }
        for (var $v_3 = 0; $v_3 < $v_1; $v_3++) {
            $v_0.append('<div>');
            this.$I_2.$7Q_1($v_0, $p0[$v_3], $v_3);
            $v_0.append(this.emptY_DIV);
            $v_0.append('</div>');
        }
        this.setInnerHtml($v_0.toString());
        ColourCalendar();
    }
  
SP.UI.ApplicationPages.CalendarStateHandler.prototype.onItemsSucceed = function($p0, $p1) {
  if (this.$K_1.$8G_0()) {
            this.$28_1();
            return;
        }
        this.$41_1 = false;
        if (this.$3G_1) {
            this.$D_1.$4T_1();
            this.$3G_1 = false;
        }
        if (SP.UI.ApplicationPages.SU.$2(this.$39_1[this.$j_1])) {
            this.$39_1[this.$j_1] = [];
        }
        Array.addRange(this.$39_1[this.$j_1], $p0);
        this.$D_1.$7S_1(this.$j_1, this.$v_1, $p1, this.$39_1[this.$j_1]);
        this.$j_1++;
        this.$1h_1();
  ColourCalendar();
 }
}
  
function ColourCalendar() {
        if(jQuery('a:contains(' + SEPARATOR + ')') != null)
        {            
   jQuery('a:contains(' + SEPARATOR + ')').each(function (i) {
   $box = jQuery(this).parents('div[title]');
   var colour = GetColourCodeFromCategory(GetCategory(this.innerHTML));
   this.innerHTML = GetActualText(this.innerHTML);
   jQuery($box).attr("title", GetActualText(jQuery($box).attr("title")));
   $box.css({'background-color': colour, 'color' : 'black !important;'});
   });       
 }  
}
  
function GetActualText(originalText) {    
 var parts = originalText.split(SEPARATOR);
 return parts[0] + parts[2];  
}
  
function GetCategory(originalText) {
 var parts = originalText.split(SEPARATOR);
 return parts[1];  
}
  
function GetColourCodeFromCategory(category) {
 var colour = null;    
 switch (category.trim()) {
  case 'Meeting':        
   colour = '#4FDB51';
   break;      
  case 'Holiday HU':        
   colour = '#01b789';
   break;      
  case 'Business':        
   colour = "#F08616";
   break;      
  case 'Holiday DE':        
   colour = "##013dbf";        
   break;      
  case 'Belgium':        
   colour = "#bf7901";        
   break;      
  case 'Birthday':        
   colour = "#6E80FA";        
   break;      
  case 'Vocation':        
   colour = "#bf0000";        
   break;    
 }    
 return colour;  
}
</script>

<script type="text/javascript"> 
var CALENDAR_LIST_TITLE = "Calendar"
 
ExecuteOrDelayUntilScriptLoaded(CustomizeCalendarEvents,"SP.UI.ApplicationPages.Calendar.js");  
 
function CustomizeCalendarEvents() {  
 
    try  
    {        
 
        var _onItemsSucceed = SP.UI.ApplicationPages.CalendarStateHandler.prototype.onItemsSucceed;    
        SP.UI.ApplicationPages.CalendarStateHandler.prototype.onItemsSucceed = function($p0, $p1) {   
            var clientContext = new SP.ClientContext(); 
            //get calendar list
            var calendarList = clientContext.get_web().get_lists().getByTitle(CALENDAR_LIST_TITLE);
 
            //get the value of the icon column for each event
            var items = [];
            for(var i=0; i<$p0.length; i++)   
            {  
                var eventId = $p0[i].$11_0; 
                var calendarListItem = calendarList.getItemById(eventId);
                clientContext.load(calendarListItem, 'Icon');
                items.push(calendarListItem);
            }
 
            //execute query
            clientContext.executeQueryAsync(Function.createDelegate(this, function()
            { 
                for(var i=0; i<$p0.length; i++)   
                { 
                    //get icon
                    var icon = items[i].get_item('Icon') 
                    if(icon && icon.$2_1 )
                    {
                        //append icon to the event titel
                        $p0[i].$3Q_0 = $p0[i].$3Q_0 + "<img src='" + icon.$2_1 + "' /> " 
                    }
                }
                //call original onItemsSucceed
                _onItemsSucceed.call(this, $p0, $p1);  
            }), Function.createDelegate(this, function(){ 
                //call original onItemsSucceed
                _onItemsSucceed.call(this, $p0, $p1); 
            }));
         }; 
    } 
    catch (err) { 
        console.log('An error occured:' + err.message);
    }  
}
 </script>