**How to calculate the number of seconds in a day?**

You can tell how many seconds are in a day very easily by an online calculator. This can be processed via the internet on a website or through an Android or iOS app. The how many seconds in a day calculator helps you figure out the exact seconds in a day. It also aids you in computing the number of seconds in any random number of days.

The days to seconds conversion calculator even lets you know the hours, minutes, seconds or milliseconds. There are even more specifications than this that take place in a single day. One of these online calculators is called “Mycalcu” where you get the number of seconds in a day. Or even the number of seconds in “x” days. The steps for this calculation are precise and quick online. However, the traditional mathematical method is followed nonetheless. Days can be very conveniently converted to seconds with just a matter of clicks.

The basic logic behind this is that there are 24 hours in a day. Every hour has a total of 60 minutes. Every minute has in turn 60 seconds. So to calculate the number of seconds in a day you just need to multiply hours times minutes times seconds. Hence this gives you 24*60*60 = 86400 seconds in one day.

Alternatively if you want to find out the number of hours in “x” days then follow this general formula. “X” days = “x” * 86400 seconds. For instance you want to know how many seconds are there in 12 days. 12 days = 12 * 86400 = 10368000 seconds. There are numerous definitions of a day. The sidereal day is the time which is relative to fixed stars so they rotate 360 degrees. The time we consider is the mean solar day. It is the time for one rotation with respect to the sun.

**What is the definition of a second?**

Second is a base unit of time but it necessarily is not the smallest unit. In all its essence the meaning of a base unit is that all other units rely on it for calculation. Therefore, any unit measuring time such as hours, minutes, nanoseconds would rely on seconds for their calculations. An hour depends on minutes and every minute depends on seconds.

This is what sums up the meaning and brings it down to the base unit. Everyone has learnt in school that a seconds depends on the rotation cycle of the Earth. This is what points to the fact that every second of an average solar is equal to 86,400. So the most accurate representation for the number of seconds in a day is due to the earth’s rotation cycle. It even amounts to the speed at which the earth rotates. Our one second radiation cycle is also attributed to the atomic clock.

Along with this another theory relating to leap seconds also comes in handy. If you want to further explore the concept of seconds by going into detail then you will have to research leap seconds. This is due to the variations in astronomical years. Our day is made up of twenty four hours in total. This is the estimated time that it takes the Earth to revolve on its axis. This revolving motion is what depends on the sun movement in the solar system. It makes up the SI unit that measures time in the metric system.

**Why are there 24 hours in a day?**

For the calculation of the number of seconds in a day, one must be aware that there are 60 minutes in 1 hour. And 60 seconds in 1 minute. Today the decimal system is mostly used and it has the base 10. This was started to make it easier for humans to count using their fingers. There were other civilisations that divided the day into smaller parts. They make use of other numeral systems, for instance duodecimal with base 12.

Sexagesimal with base 60 is used too. According to many historians Egyptians were the first civilisation to divide the day into smaller parts. This is because of their use of sundials. The very initial sundials were just stacks placed in the ground. These tell time by the length and direction of the resulting shadow. By 1500 B.C. the Egyptians had developed an advanced version of the sundial. It was like a T-shaped bar placed in the ground.

The device was calibrated into 12 equal parts to describe the intervals between sunrise and sunset. This division was in part due to Egypt’s duodecimal system. Number 12 has been given importance as it equals the lunar cycles in a year. This also symbolizes the number of finger joints on each hand. There are three in each of the four fingers without including the thumb. Therefore, counting to 12 using the thumb is not achievable.

The sundial that was innovated as the next-generation one perhaps may represent what we now refer to as the hour. Even if the hours in a day are equal, their length may be varied throughout the year. Summers can have longer hours than winters. When there was no concept of artificial light, people thought that the sunlit and dark periods were parts of two opposing realms. They didn’t think of them as being part of the same day.

**Historical significance **

Without sundials dividing the dark interval between sunset and sunrise was considered more work than merely dividing the sunlit period. This all marked the origin of how seconds in a day can be calculated. When sundials first came into use, Egyptian astronomers observed a set of 36 stars which divided heaven into equal parts.

Night passing was then marked by watching 18 of these stars. Three amongst these were credited to the two twilight periods when the stars were difficult to view. Darkness was marked by 12 of the remaining stars which once again signaled to 12 equal divisions of night. This was evidence for the duodecimal system. The New Kingdom dated from 1550 to 1070 B.C. This system used 24 stars and 12 of these signaled the passage of night. The clepsydra or water clock recorded time at night. It was the most accurate time keeping device that people of the ancient world made use of.

As long as 1400 B.C. timepiece was a specimen which was found at the Temple of Ammon in Karnak. This was a vessel with slanted interior surfaces. They allowed decreasing the water pressure and had a scale inscribed with marks dividing the night into 12 parts. This was over a course of some months. The 24 hour day concept became believable once the light and dark hours were divided into 12 parts. Nevertheless, it was not until the Hellenistic period that the fixed-length hours originated.

Greek astronomers then used such a system for their theoretical calculations. Hipparchus had his work set for 147 and 127 B.C. He decided to divide his day between 24 equinoctial hours. This is based on the 12 hours of sunlight and 12 hours of equal darkness on the equinox. Regardless of this, the lay people still used seasonally varying hours for the next few centuries. There were hours of fixed length that became common once the mechanical clocks appeared in Europe in the 14th century.

**Evolution of measuring time **

Timekeeping has always been under debate as people have relied on so many different elements to keep track of time. However, minutes and seconds were not common until centuries later following the Almagest. Clocks were introduced that divided the hour into halves, thirds, quarters or even 12 equal parts. But these were never 60. Thus, the hour was never thought to be amounting to 60 minutes in ancient times. Only after the first mechanical clocks appeared by the end of the 16th century. The general public made use of minutes to measure times. Some people even today prefer watches and clocks that display minutes instead of seconds. Ancient civilisations have been vigilant of timely divisions. This has been continued in modern society as well for a day is made up of 24 hours, an hour of 60 minutes and a minute of 60 seconds.

Astronomical events have been divided into smaller parts and this is where the concept of seconds first came from. The international system of units called SI defined seconds as a fraction of the mean solar day. They later on even related it to the tropical year. The change came in 1967. When the seconds were believed to have a duration of 9,192,631,770 energy transitions of the cesium atom. This system came into practice at the time of atomic timekeeping and Coordinated Universal Time (UTC). Leap seconds are sometimes added to UTC so the atomic time is kept in agreement with the astronomical time. Therefore, not all minutes comprise 60 seconds. A few may even contain 61 seconds.