Yes, it affects me profoundly. I am usually a little calmer in the winter after the clocks have moved back to what I think of as real time. The darkness and cold is cozy and soothing to me. I don't like the summer at all, everything is too harsh and overexposed and overstimulating. Not just the light but also the heat, the bugs, the noise, the people.

Especially after daylight saving time kicks in, the long and bright light is very bad for me. It tends to make me very irritable and dysphoric and it worsens my insomnia. I feel like it's all just one big never-ending day with no time to wind down. I haven't paid very close attention to it but I believe my worst mixed episodes are in the summer. Now there's more and more talk of getting rid of time changes, but instead of going to the proper time, many people want to stick with DST forever because they associate it with summer. That would be an absolute nightmare for me.