Can I adapt this for MY SQL backend?
Yes, you just need to adjust the $db variable initialization in _db.php:
$db = new PDO('sqlite:daypilot.sqlite');
For MySQL you'll need to use something like this:
$host = "127.0.0.1";
$port = 3306;
$username = "username";
$password = "password";
$database = "daypilot";
$db = new PDO("mysql:host=$host;port=$port",
$db->exec("CREATE DATABASE IF NOT EXISTS `$database`");
Thank you so much for such a swift reply.