How to simplify an array so that each date is only 1 time?

Question

PHP

there is an array with dates, they are repeated there 50+ times, how to make each date only 1 time?

Array
(
    [0] => Array
        (
            [users_id] => 19
            [date] => 2020-04-01
        )

    [1] => Array
        (
            [users_id] => 133
            [date] => 2020-04-01
        )

    [2] => Array
        (
            [users_id] => 87
            [date] => 2020-04-01
        )

    [3] => Array
        (
            [users_id] => 43
            [date] => 2020-04-01
        )

    [4] => Array
        (
            [users_id] => 132
            [date] => 2020-04-01
        )

    [5] => Array
        (
            [users_id] => 108
            [date] => 2020-04-01
        )
    [6] => Array
        (
            [users_id] => 108
            [date] => 2020-04-02
        )
 [7] => Array
        (
            [users_id] => 132
            [date] => 2020-04-02
        )
и т.п

Answer 1

array_unique(array_column($arr, 'date'));