How Did People Wake Up on Time Before Alarm Clocks?

Man waking up to alarm

Timekeeping technology has come a long way from ancient Egyptian sundials, and with it, so has the ability to wake up at whatever precise time might be needed for work, school, or appointments — even if we often ignore a ringing alarm in favor of snoozing for just 10 more minutes. While the demands of modern society are certainly more rigid than they once were, people have long had various reasons to keep a tight schedule, and at times they had to rely on more than just the crow of the rooster or the chirping of birds at dawn to make sure they were up to meet the day.

The most basic way people woke up before the invention of alarms was strictly biological in nature. Long before the advent of mechanical clocks or artificial light, people lived in harmony with the natural rhythms of day and night. Two biological processes dictate this natural sleep-wake cycle: homeostasis and circadian rhythms. Homeostasis governs our body’s drive for sleep, which increases the longer we’re awake and dissipates once we fall asleep, eventually signaling when it’s time to wake up. Circadian rhythms, meanwhile, control alertness and drowsiness throughout the day, influenced by light (more alert) and darkness (sleepy time).

This isn’t the only internal body process that served as a primal wake-up call before alarm clocks: Some people relied on their bladders. In biographer Stanley Vestal’s 1984 book about the life of 19th-century Lakota warrior White Bull, he noted, “Indian warriors could determine in advance their hour of rising by regulating the amount of water drunk before going to bed.” Of course, these bodily functions still exist as natural wake-up calls, but circadian rhythms often get disrupted by modern light sources such as screens, and given the strict nature of our 21st-century work schedules, one’s bladder might not be the most reliable alarm.

Another historical method of awakening also involves water, though not drinking it in large quantities. In the fourth century BCE, the ancient Greek philosopher Plato notably refined the timekeeping tool known as the "clepsydra" or "water thief” into a primitive alarm clock. Throughout the night, one basin of water would empty into another. When the water rose to the desired level, it was then siphoned into another container, emitting a whistling sound and ensuring neither Plato nor the students of his famed academy slept through his lectures. Another creative yet complicated hydraulic device was the “Water-Driven Spherical Birds’-Eye-View Map of the Heavens,” one of the first known mechanical clocks, created in 725 CE by Chinese mathematician and inventor Yi Xing. Water flowed through its system of wheels, hooks, pins, shafts, locks, and rods; the wheel did a full revolution every 24 hours, and different sounds occurred at specific times — a bell would chime every hour, and a drumlike beat would sound every 15 minutes.

Clocks using weights or pendulums, including devices with built-in alarm functionality, became much more accurate throughout the 17th and 18th centuries, but they remained largely out of reach for most people. Then, during Britain’s Industrial Revolution, the shift from agriculture to factory work created a demand for reliable timekeeping for more people than ever. Urbanization meant fewer people waking to the rooster’s crow, so instead, they depended on factory whistles, or, for those who could afford it, on “knocker-uppers” to ensure they woke up on time.

Credit: Smith Archive/ Alamy Stock Photo

Knocker-uppers were people who carried sticks, poles, or peashooters to tap on windows and wake the sleeping workers who had hired them as personal alarms. The knocker-uppers themselves were often night owls, waking for the day at 4 p.m. and retiring to bed after getting the laborers off to work. Eventually, electric alarm clocks became readily accessible to most people, but even as the gadgets gained popularity throughout the 1930s and ’40s, knocker-uppers were still found in some pockets of industrial England all the way up to the 1970s.