The 24-clock is used by militaries, most European countries, and businesses engaged in 24-hour operations, like airlines and railroads. Convert military time to regular time with the Military Time Converter. This calculator also does conversion to military time from regular time. Although the phrase "military time" is commonly used, this time system was not invented by the military. The 24-hour clock had already been employed throughout Europe for years before the U.S. military adopted it. Military time is a 24-hour clock designed to avoid confusion between daytime and nighttime hours, since the armed forces are in operation around the clock. In most countries, computers by default show the time in 24-hour notation. For example, Microsoft Windows and macOS activate the 12-hour notation by default only if a computer is in a handful of specific language and region settings. The 24-hour system is commonly used in text-based interfaces. POSIX programs such as ls default to displaying timestamps in 24-hour format. It is based on a 24 hour clock, and is a method of keeping hours in which the day runs from midnight to midnight and is divided into 24 hour increments.