How do I add a time difference to an array with PHP?
<p>I have the following array structure in MySQL. There could be no items or many items; the example shows only three.</p>

<pre><code>Array
(
    [0] =&gt; Array
        (
            [id] =&gt; 1
            ...
            [start_time] =&gt; 09:00:00
            [finish_time] =&gt; 10:20:00
            ...
        )

    [1] =&gt; Array
        (
            [id] =&gt; 2
            ...
            [start_time] =&gt; 13:00:00
            [finish_time] =&gt; 14:20:00
            ...
        )
    [2] =&gt; Array
        (
            [id] =&gt; 23
            ...
            [start_time] =&gt; 18:05:00
            [finish_time] =&gt; 19:35:00
            ...
        )

     etc etc

)
</code></pre>

<p>I want to add the time difference between start_time and finish_time and find out the total time with PHP. </p>

<p>For example, the above should produce 250min or 4 hr 10min (80 min + 80min + 90min). How do I do this?</p>
