title: Find next time business is open; mysql hours calculation
body: <p>I’m trying to figure out if a shop is currently within its opening hours, if not then select the next time its open.</p>
  
  <p>Finally I need to be able to put the opening day as a specific date.</p>
  
  <p>Can someone possible give me a tip how to construct this query?</p>
  
  <p>Thanks in advance</p>
  
  <pre><code>CREATE TABLE `shop_hours` (
    `id` int(11) NOT NULL,
    `shop_id` int(11) unsigned NOT NULL,
    `day_of_week` int(11) unsigned NOT NULL,
    `open_time` time NOT NULL,
    `close_time` time NOT NULL,
    PRIMARY KEY (`id`)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
  
  INSERT INTO `shop_hours` (`id`, `shop_id`, `day_of_week`, `open_time`, `close_time`)
  VALUES
      (1, 1, 0, '08:00:00', '24:00:00'),
      (2, 1, 1, '08:00:00', '24:00:00'),
      (3, 1, 2, '08:00:00', '24:00:00'),
      (4, 1, 3, '08:00:00', '24:00:00'),
      (5, 1, 4, '08:00:00', '24:00:00'),
      (6, 1, 5, '08:00:00', '24:00:00'),
      (7, 1, 6, '08:00:00', '24:00:00');
  </code></pre>
  
  <p><strong>Edit:</strong></p>
  
  <p>To clarify a little I'm not looking to find open shops, but only open hours for ONE specific shop. Based on the opening/closing hour, and what time it is now. I will generate some selectable timestamps incremented by 15 minutes.</p>
  
  <p>E.g. if a shop has just closed (1PM), I will need to use the next open day's open/closing time instead. (the shop isn't necessarily open every day, could be closed Sundays).</p>