OpenLayers trying to use cluster strategy and filter strategy on the same layer

Question

I have a cluster strategy being used on a vector layer that is working correctly. However, when I try and add the filter strategy to the vector layer, the filtered data does not appear on the map, in fact when I add the filter strategy, neither the cluster strategy or filter strategy appear on the map. I only see the base layer. I've seen the example in the OpenLayers 2.12 documentation; I have even hardcoded the property 'Value' to see if it would work but it doesnt work. Here is my code:

var year_filter = new OpenLayers.Filter.Comparison({
     Type: OpenLayers.Filter.Comparison.BETWEEN,
     Property: “start_date”,
     Value: '2012/04/22',
     lowerBoundary: new Date(2012, 01,01),
     upperBoundary: new Date(2013, 11, 30)
});

var cluster_strategies = [new OpenLayers.Strategy.Cluster({distance: 42})];
var filter_strategies = [new OpenLayers.Strategy.Filter({filter: year_filter})];
var layer_name = “Active Assignments”;

mapVars.activeAssignmentLayer = new OpenLayers.Layer.JsonLayer(layer_name, {
    location: “/assignments/index.json?mode=active”,
    attributeMap: [“name”, “start_date”, “end_date”, “city”]
    }, 
    {
    strategies: [cluster_strategies, filter_strategies],
    styleMap:  mapVars.clusterStyleMap
});

mapVars.map.addLayer(mapVars.activeAssignmentLayer);
mapVars.activeAssignmentsLayer.setVisibility(visibility);