The minute is a unit of time or of angle. As a unit of time, the minute is equal to 1⁄60 (the first sexagesimal fraction) of an hour or 60 seconds. In the UTCtime standard, a minute on rare occasions has 59 or 61 seconds, a consequence of leap seconds. As a unit of angle, the minute of arc is equal to 1⁄60 of a degree or 60 seconds (of arc). Although not an SI unit for either time or angle, the minute is accepted for use with SI units for both. The SI symbols for minute or minutes are min for time measurement, and the prime symbol after a number, e.g. 5′, for angle measurement. The prime is also sometimes used informally to denote minutes of time.
In old astronomical texts, minute can also mean a unit of time equal to 1⁄60 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's year as 10759D12', that is 10759 (Earth) days, 4 hours, and 48 (usual) minutes (roughly 29.5 years).