对数组对象根据时间倒序排列

在接口中查询出来的数据是这样的：

"contents": [
{
"itemContent": "问题提出",
"createdOn": 2017-01-6,
"itemType": 0,
"imgs": []
},
{
"itemContent": "回答",
"createdOn": 2017-01-12,
"itemType": 2,
"imgs": []
},
{
"itemContent": "小毕",
"createdOn": 2017-01-12,
"itemType": 2,
"imgs": []
},
{
"itemContent": "456456465",
"createdOn": 2017-01-13,
"itemType": 2,
"imgs": []
},
{
"itemContent": "礼拜四",
"createdOn": 2017-01-13,
"itemType": 2,
"imgs": []
}
]

从数据中可以看出，查出来的数据是由时间的升序排序的，有什么方法让这个数组中的对象按时间倒序排列？我想要的结果是这样的：

"contents": [
{
"itemContent": "礼拜四",
"createdOn": 2017-01-13,
"itemType": 2,
"imgs": []
},
{
"itemContent": "456456465",
"createdOn": 2017-01-13,
"itemType": 2,
"imgs": []
},
{
"itemContent": "小毕",
"createdOn": 2017-01-12,
"itemType": 2,
"imgs": []
},
{
"itemContent": "回答",
"createdOn": 2017-01-12,
"itemType": 2,
"imgs": []
},
{
"itemContent": "问题提出",
"createdOn": 2017-01-6,
"itemType": 0,
"imgs": []
}
]

使用reverse() 颠倒数组中元素的顺序，这时，arr中的对象已经颠倒过来了，比排序还要简单

var arr = contents.reverse();