The tropical year is a unit of time that is a multiple of an SI unit. We have used the symbol at.
The average tropical year up to the year 2000 was 365.2422 days of 86400 seconds.
The phrase “tropical” comes from the Greek for “turn”; tropikos. Following this, and where the “turn” referred to is the same as that defining the tropics of Capricorn and Cancer (the extreme latitudes North and South where the sun can still appear directly overhead or perpendicular to the Earth’s surface); a tropical year is known as the time it takes the sun to complete a full cycle of seasons and return to the same relative position to the observer on Earth.
In 1627, Johannes Kepler used the findings of Tycho Brahe and Waltherus (the Rudolphine Tables) to establish the mean tropical year as 365 solar days, 5 hours, 48 minutes and 45 seconds.
The minute is a unit of time and is a multiple of an SI base unit with the symbol m.
There are 60 seconds in a minute. There are 60 minutes in an hour.
The Iranian scholar and polymath Al-Biruni who lived through the Islamic Golden Age (circa 1000 AD) was the first to split the hour sexagesimally (by 60) and introduced what we now understand as the “minute”.
It is understood in modern society to represent a relatively short amount of time – and is used very commonly in language to ask for a short break; hence the phrase “wait a minute”, “uno momento” and “un moment s’il vous plait”.