Choose a Measurement
Select a measurement and convert between different units
Single conversion
To convert from Hour (h) to Year (year), use the following formula:
Let's convert 5 Hour (h) to Year (year).
Using the formula:
Therefore, 5 Hour (h) is equal to Year (year).
Here are some quick reference conversions from Hour (h) to Year (year):
| Hours | Years |
|---|---|
| 0.000001 h | year |
| 0.001 h | year |
| 0.1 h | year |
| 1 h | year |
| 2 h | year |
| 3 h | year |
| 4 h | year |
| 5 h | year |
| 6 h | year |
| 7 h | year |
| 8 h | year |
| 9 h | year |
| 10 h | year |
| 20 h | year |
| 30 h | year |
| 40 h | year |
| 50 h | year |
| 100 h | year |
| 1000 h | year |
| 10000 h | year |
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.
A year is the time it takes for the Earth to complete one full orbit around the Sun.
We commonly think of a year as 365 days, but it's not quite that simple. The Earth's journey actually takes a little longer, which is why our calendar needs a special trick to stay accurate.
The Earth takes approximately 365.24 days to travel around the Sun. That extra quarter of a day might not seem like much, but it adds up over time.
To keep our calendar in sync with the Earth's orbit and the seasons, we add an extra day—February 29th—nearly every four years. This is called a leap year.
Without leap years, our calendar would drift by about 24 days every 100 years, and eventually, we'd have summer in December!
Yes! While our calendar uses a 365-day system, scientists use more precise measurements depending on what they're tracking.
The two most common types of years are:
The idea of a "year" can get much, much bigger. Just as the Earth orbits the Sun, our entire solar system orbits the center of the Milky Way galaxy.
This enormous journey is called a Galactic Year (or cosmic year), and it takes an estimated 230 million Earth years to complete. To put that in perspective, the last time our solar system was in this exact spot, dinosaurs were beginning to roam the Earth during the Triassic period.