I am struggling with this. Sorting a multi-dimensional array by value based on dates. Here is a snippet of the array:

```
Array
(
    [0] => Array
        (
            [clicks] => 14
            [point] => 11 February 2011
        )

    [1] => Array
        (
            [clicks] => 1
            [point] => 14 February 2011
        )

    [2] => Array
        (
            [clicks] => 8
            [point] => 15 February 2011
        )

    [3] => Array
        (
            [clicks] => 0
            [point] => 08 February 2011
        )

```

I would like to sort it by date with the keys in the correct order. So in this case the `08 February 2011` should get key `0`. I tried to make use of usort but that didn't go well as I couldn't even make use of the callback function in codeigniter which is another problem I am researching. 

What is the most efficient way of doing this? My array can grow to 60 entries.

Thanks all for any help.