Interesting topic and seems like a reasonable thing to study. It would be cool to see a study where participants behave in a way that leads to more light exposure in month A and the opposite in month B, randomising the time ordering etc.

Despite power analysis and all the “50 people convenience sample, mostly observing based on what people do anyway” seems a bit like it won’t really lead to any action guiding outcomes beyond vaguely confirming people’s priors? As in, perhaps this style of research is not ambitious enough in a way?