php拆分合并新数组的开始时间和结束时间

First all; I'm sorry if my question is not irrelevant. I'm new on array's with PHP.

I have an array;

[
    {
        "order_id":"7",
        "order_start_time":"08:00:00",
        "order_end_time":"11:00:00",
        "order_date":"29\/03\/2018"
    },
    {
        "order_id":"8",
        "order_start_time":"10:00:00",
        "order_end_time":"01:00:00",
        "order_date":"29\/03\/2018"
    }
]

I want to split time ranges from start to end by hours. Desired output;

[
    {
        "hour_selected":"08:00:00"
    },
    {
        "hour_selected":"09:00:00"
    },
    {
        "hour_selected":"10:00:00"
    },
    {
        "hour_selected":"11:00:00"
    },
    {
        "hour_selected":"12:00:00"
    },
    {
        "hour_selected":"13:00:00"
    }
]

But i'm lost how can i do this with time hour ranges. Any help greatly appricated.

PS: I'm creating array from mysql datetime field.

the simpliest solution is to use unix timestamp:

<?php

$timeFrom = '08:00:00';
$timeTo = '15:00:00';

function rangeBetweenHours($from, $to)
{
    $timeFrom = strtotime('today ' . $from);
    $timeTo = strtotime('today ' . $to);

    $out = [];
    foreach (range($timeFrom, $timeTo, 60 * 60) as $timestamp) { // 60 * 60 is a hour
        $out[] = date('H:i:s', $timestamp);
    }

    return $out;
}

var_dump(rangeBetweenHours($timeFrom, $timeTo));

Here you can see working example: http://sandbox.onlinephpfunctions.com/code/8fec4a2f6b067dc66705732b3c43301cc8722d3f

[ { "order_id":"7", "order_start_time":"08:00:00", "order_end_time":"11:00:00", "order_date":"29/03/2018" }, { "order_id":"8", "order_start_time":"10:00:00", "order_end_time":"01:00:00", "order_date":"29/03/2018" } ]

Apply for each on this and get order_start_time & order_end_time in an array then sort as per values associating as par increasing order of time.