What is second?
The second is the SI base unit of time. It is used globally in science, engineering, computing, and everyday life, and is the foundation upon which all other time units are built.
Real-world uses
The second is the SI base unit of time, fundamental to all scientific measurement, computing clock cycles, athletic timing, and GPS satellite synchronization. Everyday timekeeping, cooking timers, and traffic light cycles all rely on seconds.
History
The concept of dividing the day into 86,400 parts dates to ancient Babylonian and Egyptian timekeeping. Since 1967, the SI second has been defined as 9,192,631,770 periods of the radiation from a caesium-133 atom.
Common mistakes
Assuming a second has always been 1/86,400 of a day. The modern SI second is defined by caesium atom vibrations and is independent of Earth's rotation, which varies slightly due to tidal friction.
What is hour?
An hour is a unit of time equal to 60 minutes. It is the standard unit for time-of-day references, work schedules, travel durations, and billing periods across most global contexts.
Real-world uses
Hours are the primary unit for work schedules, flight durations, parking meters, and time zone offsets. Labour laws define maximum working hours, and electricity billing is based on kilowatt-hours of consumption.
History
The concept of dividing the day into 24 hours dates to ancient Egypt, where daylight and night were each split into 12 parts. These "hours" varied in length seasonally until mechanical clocks standardized equal hours in medieval Europe.
Common mistakes
Converting hours to minutes by multiplying by 100 instead of 60. Also, confusing 12-hour and 24-hour time formats—"12:00 AM" is midnight, not noon, which frequently causes scheduling errors.
When is this conversion used?
Converting second to hour is useful in the time domain when comparing values across different measurement standards or applying formulas that require a specific unit.
Worked examples
1 second = 0.00027778 hour
1 hour = 3,600 second
How to convert second to hour
To convert second to hour, multiply the value by 0.00027778.
To convert hour back to second, multiply by 3,600.
Measurement standards
The SI second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom, maintained by the BIPM and national metrology institutes worldwide.
Did you know?
Earth's rotation is gradually slowing due to tidal friction with the Moon. To keep atomic time aligned with solar time, "leap seconds" have been inserted 27 times since 1972 — though they are scheduled to be abolished by 2035.
Quick reference: second to hour
| second | hour |
|---|---|
| 0.1 | 0.00002778 |
| 0.5 | 0.00013889 |
| 1 | 0.00027778 |
| 2 | 0.00055556 |
| 5 | 0.00138889 |
| 10 | 0.00277778 |
| 25 | 0.00694444 |
| 50 | 0.01388889 |
| 100 | 0.02777778 |
| 250 | 0.06944444 |
| 500 | 0.13888889 |
| 1,000 | 0.27777778 |
Common values
| second | hour | |
|---|---|---|
| Blink of an eye | 0.3 second | 0.00008333 hour |
| Average pop song | 210 second | 0.05833333 hour |
| Feature film | 7,200 second | 2 hour |
| One work day (8 hrs) | 28,800 second | 8 hour |
| One calendar year | 31,536,000 second | 8,760 hour |
Available Time units
More second conversions
- Convert second to minute
- Convert second to hour
- Convert second to day
- Convert second to week
- Convert second to year (365 d)
- Convert second to millisecond
- Convert second to microsecond
- Convert second to nanosecond
- Convert second to century (100 yr)
Assumption: year is defined as 365 days and century values are approximate.