Time is a concept that is very difficult to define, even though people have been trying for ages. For millennia, it has been a very fascinating topic of discussion in religion, science and philosophy. Throughout history, humans have invented many devices to help them track time. Whether that’s the time of day, day of the week or simply the year we are living in, having a sense of time is very important.

Measuring time

When it comes to measuring time, we use events in space-time as references. For example, one day is one rotation of the Earth around its axis, and a year is one rotation of the Earth around the Sun. So if someone is 25 years of age, that means they have survived for 25 full rotations of the Earth around the Sun. Of course, time would pass even if the earth stopped, however it is easier to understand time with these factors. One day lasts exactly 24 hours, or 1440 minutes, while one year lasts around 365 days, or 8760 hours.

The most basic unit of measuring time is a second. We can also use the SI system designated prefixes with seconds to describe larger or smaller time intervals. There is almost no reason to use the multiples, as we have more mainstream units for larger time intervals. Those are minutes, hours, days, weeks, months, years, decades, centuries and millennia.

When it comes ti using submultiples for seconds, they are very rarely used because they are so difficult to grasp. For example, 1 attosecond is 10^-18 seconds. That is exceptionally small, but how small is it actually? Let me give you a reference for this.

The speed of light is 2.998*10^8 m/s. An attosecond is so small, in 3 attoseconds, light can only travel from one side of an atom to the other. Knowing the diameter of an atom is 10^-5 m, we can easily prove this using math:

2.998*10^{8} \frac {m}{s} * 10^{-18}s = 2.998*10^{-10} s


Humans, during their lives, change a lot, both physically and psychologically. Recording time has made it easier for us to track these changes. For example, it is common knowledge that humans grow until they are about 25 years of age. At that point, they are in their physical prime.

We find great importance in remembering important dates. Whether that’s your birthday, someone else’s birthday or a widely accepted holiday, you have to remember it. When it comes to birthdays specifically however, it goes without saying you have to know how old you are at all times. Many laws require you to be of certain age to do certain things.

In most of the world, after 18 years of life, a person will become an adult. There are a few countries, namely New Zealand, Japan, Taiwan and Thailand, where the age of adulthood is 20. When it comes to the us, even though you are an adult at 18, you can drive at 16, but you can’t drink alcohol until you are 21.

Our age calculator can calculate your exact age, down to minutes and even seconds! All you need to do is input your date of birth and the calculator will do the rest.