Проверка времени ввода PHP
preg_match("/^(?:2[0-4]|[01][1-9]|10):([0-5][0-9])$/", $foo)
Half Unicorn, Half Potato
preg_match("/^(?:2[0-4]|[01][1-9]|10):([0-5][0-9])$/", $foo)