Please see this example where sort by a date field works fine: http://jsfiddle.net/v120zxm2/1/
<script src="https://cdn.zoomcharts-cloud.com/1/latest/zoomcharts.js"></script>
<div id='demo1' style='width:100%; height:300px;'></div>
<div id='demo2' style='width:100%; height:300px;'></div>
var data = {
subvalues: [
{name: "Safari (in-app)", value: 549, "id": "Safari (in-app)", date: new Date(2015,2,12)},
{name: "Mozilla Compatible Agent", value: 296, "id": "Mozilla Compatible Agent", date: new Date(2014,2,12)},
{name: "Playstation 3", value: 204, "id": "Playstation 3", date: new Date(2016,3,1)},
]
};
var f1 = new FacetChart({
container: document.getElementById("demo1"),
data: {
preloaded: data,
sortField: "date"
}
});
var f2 = new FacetChart({
container: document.getElementById("demo2"),
data: {
preloaded: data,
sortField: "-date"
}
});