What effect would a different day/night cycle, and by extension, sleep cycle, such as on Uranus, have on biological ageing?

Astronauts on the International Space Station (ISS) have sun rises and sun sets every 90 minutes. I would start by asking them this question.
Evolution will adjust and we would have another species of human that is adapted to the change in environment.

Based on Earth Standard Time, no difference whatsoever.

Since the harnessing of electricity, our sleep cycle has little to do with the hours of daylight anymore.

I think shorter days would only speed up the discovery or invention of a power that would make the length of days inconsequential.

Our biological clocks run on their own time and not influenced by any outside sources, under normal conditions.

There is no difference in longevity expectations for people who live at the equator and people who live at high latitudes, so I would posit day length doesn’t have an effect.

Look at those people that live above the Arctic Circle. They go through long periods of daylight followed by long periods of darkness. I don’t believe this has any particular impact on biological aging.

Probably would negatively impact it. Proper sleep is about the best anti-aging remedy there is.