Hour markers, also known as indices, are essential components on a watch dial that indicate the hours. They serve both functional and aesthetic purposes, guiding the wearer in reading the time accurately and enhancing the watch's design. There are several types of hour markers, each offering a distinct style and level of legibility.

Applied indices are three-dimensional markers affixed to the dial, often made from metal or luminous materials, providing a premium look and improved visibility. Roman numerals, characterized by their classic I, II, III format, lend a traditional and elegant appearance, commonly found on dress watches. Arabic numerals, using the familiar 1, 2, 3 sequence, offer a modern and easily readable option, frequently seen on sports and casual watches.

The choice of hour markers significantly influences a watch's overall aesthetic and usability. Applied indices can add depth and luxury, while Roman numerals evoke a sense of timelessness. Arabic numerals are favored for their clarity and contemporary appeal. Each type of hour marker not only aids in time-telling but also reflects the watchmaker's design philosophy, contributing to the watch's identity and the wearer's personal style.