RangeSeparator.php

<?php

namespace Acme\Util\Time;

class RangeSeparator
{
    /**
     * @param string $start
     * @param string $end
     * @param string $daily
     * @param string $hourly
     * @return array
     */
    public function separateByDH($start, $end, $daily, $hourly)
    {
        if (strtotime($daily) > strtotime($hourly)) {
            throw new \InvalidArgumentException('Daily stop must be bigger than hourly stop.');
        }

        return $this->separate($start, array_filter([
            'daily' => $daily,
            'hourly' => $hourly,
            'rest' => $end,
        ]));
    }

    /**
     * @param string $current
     * @param array $stops
     * @return array
     */
    private function separate($current, array $stops)
    {
        $results = [];

        foreach ($stops as $key => $stop) {
            if (strtotime($stop) > strtotime($current)) {
                $results[$key] = [$current, $stop];
                $current = $stop;
            }
        }

        return $results;
    }
}

$range = new RangeSeparator;

$start = '2015-05-01 00:00:00';
$end = '2015-05-02 12:00:00';
$daily = '2015-05-02 00:00:00';
$hourly = '2015-05-02 11:00:00';

$result = $range->separateByDH($start, $end, $daily, $hourly);
#=> array(3) {
#     'daily' =>
#     array(2) {
#       [0] =>
#       string(19) "2015-05-01 00:00:00"
#       [1] =>
#       string(19) "2015-05-02 00:00:00"
#     }
#     'hourly' =>
#     array(2) {
#       [0] =>
#       string(19) "2015-05-02 00:00:00"
#       [1] =>
#       string(19) "2015-05-02 11:00:00"
#     }
#     'rest' =>
#     array(2) {
#       [0] =>
#       string(19) "2015-05-02 11:00:00"
#       [1] =>
#       string(19) "2015-05-02 12:00:00"
#     }
#   }