Electric lighting changed bedtime habits by making evening activity possible for many more hours.

The longer version

Affordable artificial light detached evening activity from sunset, pushing bedtime later and compressing time in bed. Gas lamps did some of this in cities, but widespread electric lighting extended the usable evening by several more hours. Reading, socialising and shift work all became practical after dark in a way they had not been before.

Later light exposure also feeds back onto the body clock, delaying its schedule for anyone exposed after dark. Historians trace the change through falling candle use and later recorded bedtimes. The change also altered when people met light, with consequences for the internal clock that researchers are still examining. The shift ranks among the largest behavioural changes of that era.

Where this entry sits

This collection gathers curious details about sleeping and dreaming, from nightly brain stages and body clocks to naps, yawns and unusual animal habits. It also covers how bedtime customs have changed across centuries, without offering any advice. The full list sits on the Sleep and Dreams page, where every entry is listed in order.