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To convert from Hour (h) to Second (s), use the following formula:
Let's convert 5 Hour (h) to Second (s).
Using the formula:
Therefore, 5 Hour (h) is equal to Second (s).
Here are some quick reference conversions from Hour (h) to Second (s):
| Hours | Seconds |
|---|---|
| 0.000001 h | s |
| 0.001 h | s |
| 0.1 h | s |
| 1 h | s |
| 2 h | s |
| 3 h | s |
| 4 h | s |
| 5 h | s |
| 6 h | s |
| 7 h | s |
| 8 h | s |
| 9 h | s |
| 10 h | s |
| 20 h | s |
| 30 h | s |
| 40 h | s |
| 50 h | s |
| 100 h | s |
| 1000 h | s |
| 10000 h | s |
An hour (h) is a universal unit of time equal to 60 minutes, or 3,600 seconds.
The practice of breaking the day into smaller parts goes back to ancient civilizations, especially the Egyptians. They divided daylight and nighttime into 12 hours each, creating the 24-hour day.
During the day, they used shadow clocks—an early form of sundial—to tell the hours, and at night, they tracked groups of stars called decans to mark the hours.
This system, known as a duodecimal (base-12) system, was convenient as the number 12 has many factors, making it easy to subdivide.
The reason we divide an hour into 60 minutes and a minute into 60 seconds comes from the ancient Babylonians. They used a sexagesimal (base-60) numbering system for their mathematical and astronomical calculations.
This system was likely adopted because 60 is a highly composite number, having twelve factors (1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60). This made it exceptionally easy to calculate fractions.
The Greek astronomers Hipparchus and Ptolemy later adopted this system for their astronomical work, solidifying its use in measuring time and angles (like the 360 degrees in a circle).
While an hour is commonly defined as 3,600 seconds, its ultimate precision is tied to the modern definition of a second.
According to the International System of Units (SI), a second is the duration of 9,192,631,770 cycles of the radiation emitted during the transition between two energy levels of the caesium-133 atom.
Therefore, a modern hour equals exactly 3,600 seconds — 3,600 times this atomic standard — making it an exceptionally stable, universally consistent unit of time verified by atomic clocks around the world.
Have you ever stopped to think about what a "second" really is?
As the base unit of time in the International System of Units (SI), the second is a fundamental part of our daily lives. But its definition has an intriguing history — from tracking the Sun's movements to measuring the vibrations of a single atom.
While we used to define a second based on the Earth's rotation around the Sun, that method wasn't precise enough for modern science.
Today, the official definition of a second is based on the incredibly consistent and reliable atomic clock.
So, what does that mean? Officially, one second is the time it takes for a caesium-133 atom to oscillate (or vibrate) exactly 9,192,631,770 times. Think of it as a tiny, perfectly predictable pendulum.
This atomic standard is far more stable than measuring the Earth's rotation, which can vary slightly.
The reason we divide minutes and hours into 60 parts dates back thousands of years to the ancient Babylonians. They used a sexagesimal (base-60) numbering system for their advanced mathematical and astronomical calculations.
This practical system was passed down through Greek and Arab scholars and was eventually adopted worldwide for two primary purposes:
If atomic clocks are so perfect, why do we sometimes need to adjust them?
The problem is that the Earth's rotation is not perfectly uniform—it can speed up or slow down by tiny fractions of a second.
This causes a slow drift between the time kept by atomic clocks (Coordinated Universal Time, or UTC) and the time based on the Earth's position relative to the Sun.
To fix this, we occasionally add a leap second — an extra second that keeps our clocks aligned with the solar day, so that sunrise and sunset occur when we expect them to.