The "12-hour" format is a way of telling time that divides the day into two periods: from midnight to noon (12:00 AM to 11:59 AM) and from noon to midnight (12:00 PM to 11:59 PM). This system uses numbers from 1 to 12, making it easy to read and understand for many people. In contrast to the 24-hour clock, commonly used in military and international contexts, the 12-hour format is prevalent in everyday life in countries like the United States and Canada. It is often accompanied by terms like "AM" for morning hours and "PM" for afternoon and evening hours.