I have this multidimensional array, and i want to order each array by 'fecha'(i mean 2017-02-20, then 2017-02-21, then 2017-02-22 and finally 2017-02-23). I have read a lot of answers, but they only work with bidimensional arrays. I have tried with unsort and array\_multisort, even with ksort bue i couldn´t obtain the desire result.

```
Array
    (
        [0.10] => Array
            (
                [0] => Array
                    (
                        [fecha] => 2017-02-21
                        [tarifa] => 743.80
                        [percent] => 0.10
                    )

                [1] => Array
                    (
                        [fecha] => 2017-02-22
                        [tarifa] => 743.80
                        [percent] => 0.10
                    )

                [2] => Array
                    (
                        [fecha] => 2017-02-20
                        [tarifa] => 743.80
                        [percent] => 0
                    )

                [3] => Array
                    (
                        [fecha] => 2017-02-23
                        [tarifa] => 743.80
                        [percent] => 0
                    )

            )

        [0.15] => Array
            (
                [0] => Array
                    (
                        [fecha] => 2017-02-21
                        [tarifa] => 743.80
                        [percent] => 0.15
                    )

                [1] => Array
                    (
                        [fecha] => 2017-02-22
                        [tarifa] => 743.80
                        [percent] => 0.15
                    )

                [2] => Array
                    (
                        [fecha] => 2017-02-20
                        [tarifa] => 743.80
                        [percent] => 0
                    )

                [3] => Array
                    (
                        [fecha] => 2017-02-23
                        [tarifa] => 743.80
                        [percent] => 0
                    )

            )

    )

```