- var_dump: documentation ( source)
- array_reduce: documentation ( source)
- date: documentation ( source)
- range: documentation ( source)
<?php
$result = array_reduce(range(25200, 68400, 900), function($cur, $x)
{
$cur[date('H:i', $x)] = date('g:ia', $x);
return $cur;
}, array());
var_dump($result);