Before alarm clocks were invented, there were “knocker-ups” who went tapping on client’s windows with long sticks until they were awake.
The people who did the tapping were known as “knocker ups” or “knocker uppers.” They walked the streets from early in the morning, tapping on the windows of their sleeping customers — usually men who worked shifts or odd hours — with a long pole. Alarm clocks were neither affordable nor reliable, but the knocker up was.