重新定义数组键php

I have an array.

Array
(
    [0] => Array
        (
            [TotalClicksPerDay] => 5
            [Date] => 2012-11-26
            [weekDay] => 2
        )

    [1] => Array
        (
            [TotalClicksPerDay] => 13
            [Date] => 2012-11-27
            [weekDay] => 6
        )

)

I want to redefine the keys by using the value [weekday] as the key.

So in the example above, the new array would read like so:

Array
(
    [2] => Array
        (
            [TotalClicksPerDay] => 5
            [Date] => 2012-11-26
            [weekDay] => 2
        )

    [6] => Array
        (
            [TotalClicksPerDay] => 13
            [Date] => 2012-11-27
            [weekDay] => 6
        )
)

foreach ($old_array as $values) {
    $new_array[$values['weekDay']] = $values;
}