
The First Alarm Clock Could Only Ring at 4 AM
In 1787, clockmaker Levi Hutchins of Concord, New Hampshire, built the first known personal alarm clock. However, it could only ring at 4:00 AM — the time he needed to wake up for work. He never patented or commercialized the invention. The first adjustable alarm clock was patented in 1847 by Antoine Redier in France.