"24-Hour" typically refers to a time period of one full day, consisting of 24 hours. This concept is used universally to measure time, dividing the day into two 12-hour segments: AM (morning) and PM (afternoon/evening). The 24-hour clock system is often used in military, aviation, and international contexts to avoid confusion between morning and evening times. In many cities, "24-hour" can also describe businesses or services that operate continuously throughout the day and night. Examples include 24-hour diners, convenience stores, and emergency services. These establishments provide access to goods and services at any time, catering to various needs and schedules.