You really think short-long-short-short-long is better? It seems confusing enough to be of dubious value. Why not have seasons and months be equivalent and each equal to 73 days in length? That way you'd had the 50th day of summer, for example. Sure it would require a new season, but you reduce complexity quite a bit and there is no reason to keep the existing 12 month requirement. You can align the first month/season with the first of the year and add a 0-day for leap years.

Yeah, it's kind of fun to think about...