A minute is a unit of measurement of time or of angle.

The minute is a unit of time equal to 1/60th of an hour or 60 seconds. Some rare minutes have 59 or 61 seconds; see leap second. The minute is not an SI unit, however it is accepted for use with SI units.

The symbol for minute or minutes is min.

The fact that an hour contains 60 minutes is probably due to influences from the Babylonians, who used a base-60 or sexagesimal counting system.

Geometry

In geometry, the minute is a unit of angle, 1/60th of a degree. It is also known as a minute of angle or minute of arc and can further be divided into 60 seconds of arc.

The symbol for a minute of arc is a prime (′). For example, fifteen minutes could be written 15′. However, more commonly an apostrophe, or single quote (U+0027), is used.

Astronomy

In astronomy, the minute is a unit of angle, the minute of right ascension. It is equal to 1/60th of an hour of right ascension and can be further divided into 60 seconds of right ascension.

The symbol for a minute of right ascension is min.

The Earth turns on its polar axis through fifteen minutes of arc in every minute of sidereal time. One minute of arc at the Earth's equator is approximately one nautical mile.

In old astronomical texts minute can also mean a unit of time equal to 1/60th of a day (24 usual minutes). These minutes correspond to the Latin diei scrupulis, and used to express periods of planetary motions. For example, Kepler in Harmonices Mundi gives Saturn year as 10759D12', that is 10759 (Earth) days, 4 hours, and 48 (usual) minutes.

Origin

The first division was originally known as a "prime minute", from Latin "(pars) minuta prima", meaning "first minute (i.e. small) part (or division)" of the hour. Likewise, the second was known as a "second minute", meaning "the second small division" of the hour.

References

• Henry Campbell Black, Black's Law Dictionary, 6th Edition, entry on Minute. West Publishing Company, St. Paul, Minnesota, 1991.
• Eric W. Weisstein. "Arc Minute." From MathWorld -- A Wolfram Web Resource. http://mathworld.wolfram.com/ArcMinute.html
• Definitions of the SI Units