Who came up with o'clock?

The Origins of O'Clock

Have you ever wondered why we say o'clock when telling time? It sounds like a single word, but it is actually a historical shortcut. The phrase comes from the Middle English period, evolving as people needed more precise ways to talk about time during the day.

Language historians have traced the earliest known written use of the term back to 1419. It appeared in the Guildhall Letter-book, a historical record from London. Back then, it was written as a contraction of a longer expression: "of the clock."

Before mechanical clocks became common in towns and homes, people relied on sundials, church bells, and natural daylight. As public clocks started appearing on towers across Europe, a new vocabulary followed. Saying "four of the clock" meant pointing directly to the mechanical timepiece on the wall or church steeple. Over time, everyday speech naturally sped this up, dropping the "f" and "the" to give us the familiar o'clock we still use today.