The Science of Time Measurement
Time is the only physical quantity that moves in one direction. Unlike length or weight, which use the decimal system (base-10), time measurement is based on the ancient sexagesimal system (base-60). This is why we have 60 seconds in a minute and 60 minutes in an hour. Our converter helps you navigate these complex multiplications effortlessly.
How Long is a "Year" Exactly?
A standard calendar year is 365 days, but the Earth actually takes about 365.2422 days to orbit the Sun. This small difference is why we need "Leap Years."
- Every 4 years, we add one day (Feb 29).
- Exception: Years divisible by 100 are NOT leap years (e.g., 1900).
- Exception to the Exception: Years divisible by 400 ARE leap years (e.g., 2000).
Defining the Second
For centuries, a second was defined as 1/86,400 of a solar day. However, the Earth's rotation is slightly irregular. Since 1967, the second has been defined by atomic physics.
- The Atomic Second: It is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.
- This precision allows GPS satellites and the internet to function correctly.
Frequently Asked Questions (FAQ)
How many seconds are in a day?
There are exactly 86,400 seconds in a standard day (60 seconds × 60 minutes × 24 hours).
Why is a minute 60 seconds?
This comes from the ancient Babylonians, who used a base-60 counting system. The number 60 is highly versatile because it can be evenly divided by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30, making manual calculations easier.
Disclaimer: This calculator uses the standard Gregorian calendar year (365 days) for generic year conversions.