https://github.com/hilios/jQuery.countdown/blob/master/src/countdown.js#L29

```js
if(String(dateString).match(matchers)) {
    // If looks like a millisecond value cast to number before 
    // final casting (Thanks to @msigley)
    if(String(dateString).match(/^[0-9]*$/)) {
        dateString = Number(dateString);
    }
    // Replace dashes to slashes
    if(String(dateString).match(/^[0-9]*$/)) {
        dateString = dateString.replace(/\-/g, '/');
    }
    return new Date(dateString);
}
```