Sort array of objects by single key with date value

I have an array of objects with several key value pairs, and I need to sort them based on ‘updated_at’:

[
    {
        "updated_at" : "2012-01-01T06:25:24Z",
        "foo" : "bar"
    },
    {
        "updated_at" : "2012-01-09T11:25:13Z",
        "foo" : "bar"
    },
    {
        "updated_at" : "2012-01-05T04:13:24Z",
        "foo" : "bar"
    }
]

What’s the most efficient way to do so?