The day/night indicator is a feature on world-time watches that helps distinguish daytime from nighttime hours in a given time zone. Often represented as a rotating disk with sun and moon symbols or color-coded sections (light for the day, dark for the night), it provides an obvious visual reference to travelers. This indicator is especially helpful to people tracking multiple time zones so they do not get confused when calling or planning across continents. The day/night indicator adds visual interest and functionality as an additional layer of usefulness to world-time watches.