Javascript Sorting by date time

Im currently working on a web based calendar and I needed to sort my event object by date real quick. So the first thing I did was a quick search  on sorting an object by date time. Google becomes such second nature I immediately think of doing that first sometimes before fleshing out a whole solution in my mind. The first result I was brought to was this page on about.com. While the authors solution will work I thought why do even need this complexity? This is what I came up with when I stepped away from Google realizing this was a very trivial task

/*
* Function : sortDate(Date, Date)
* Description : Sorts an object based on date
*/
function sortDate(a,b)
{
    var a = new Date(a.startDateTime),
        b = new Date(b.startDateTime);
    return (a.getTime() - b.getTime());
}

My object has a property called startDateTime, but this can easily be modified. All I do is a quick comparison of the UNIX time stamp and its sorted. Mainly just hoping this eventually ranks higher than the result I found on Google.