Well, the question was whether there is another solution. So there might be many, you just have to say, "Yes". As mentioned above, there are plenty, including "union", "negation/and", subquery, I would add CTE, etc. The answer provided is a correct one for this particular case that is rather mensa-oriented. In large scale systems, you would avoid relying on the modulo due to the fact that month list would have to be as generic as possible... As also mentioned above. However, it was fun to answer.