Many cultures once treated sleep as two separate blocks separated by a wakeful hour.

The longer version

Historical records from Europe describe first sleep and second sleep, with an interval around midnight used for prayer, reading, visiting neighbours or quiet thinking. Diaries, court records and literature all mention the pattern before the eighteenth century. Some accounts describe the interval as the quietest and most productive part of the night.

The idea that a single unbroken block is natural is fairly recent. Sleep researchers who recreated long winter nights without electric light found that participants often split sleep into two segments with a calm waking period between them. The finding is often overstated, since the written evidence comes mostly from literate households and cannot represent every region.

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.