It can be an interesting thought experiment to imagine a world where clocks didn’t exist and we hadn’t subdivided the years into named slices. We spend so much time reasoning relative to our understanding of time, which is seen through the lens of clocks and calendars.

Another perspective is one of phenomena that comes and goes based on the state of the environment and the progression of some underlying process, e.g. a plant that flowers and then goes dormant.

I know that personally, I experience very different levels of productivity and mental states based on the time of year. Spring brings a feeling of newness and possibility. Summer a desire to socialize and have fun in the sun. Winter is more contemplative and occasionally depressive.

I could definitely see my output as someone who writes things taking on different characteristics as the conditions around me ebb and flow.

As others have pointed out, I don’t think this variance is limited to a single notion of better/worse, but it definitely modulates my output.

I think productivity is lower in the winter, so I'm not sure about quality per se, but intuitively it makes sense that anything written in the winter months is less verbose.

Length doesn't mean quality; the data could also be more concise.