What is day?
A day is a unit of time equal to 24 hours, corresponding to one full rotation of the Earth. It is the primary unit for calendars, deadlines, event scheduling, and date-based calculations.
Real-world uses
Days are the fundamental unit for calendars, project deadlines, medication schedules, and billing cycles. Hospital stays, rental periods, and food expiration are counted in days. Astronomers use Julian days for continuous date numbering.
History
The day is one of the oldest natural time units, based on Earth's rotation. Ancient Egyptians were among the first to divide it into 24 hours. The seven-day week originates from Babylonian astronomy, linked to the seven visible celestial bodies.
Common mistakes
Assuming every day is exactly 24 hours. Due to daylight saving time transitions, a day can be 23 or 25 hours. Astronomers also distinguish between solar days and sidereal days (23 hours 56 minutes).
What is nanosecond?
A nanosecond is a unit of time equal to one billionth of a second. It is critical in computer processor timing, high-frequency trading, optical communications, and physics experiments.
Real-world uses
Nanoseconds are used in computing to measure memory access times (DRAM latency is typically 10–100 ns), CPU cache operations, and network packet timestamps. Light travels approximately 30 cm in one nanosecond, a fact used in signal timing.
History
The nanosecond became a practical unit with the advent of digital electronics in the 1960s. Grace Hopper famously used a 30 cm piece of wire to demonstrate the distance light travels in a nanosecond, making the concept tangible for non-engineers.
Common mistakes
Underestimating how short a nanosecond is—light only travels about one foot in a nanosecond. Also, confusing nanoseconds with microseconds in performance specifications, which differ by a factor of 1,000.
When is this conversion used?
Converting day to nanosecond is useful in the time domain when comparing values across different measurement standards or applying formulas that require a specific unit.
Worked examples
1 day = 8.640000e+13 nanosecond
1 nanosecond = 1.000000e-09 second
How to convert day to nanosecond
To convert day to nanosecond, multiply the value by 8.640000e+13.
To convert nanosecond back to day, multiply by 1.157407e-14.
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: day to nanosecond
| day | nanosecond |
|---|---|
| 0.1 | 8.640000e+12 |
| 0.5 | 4.320000e+13 |
| 1 | 8.640000e+13 |
| 2 | 1.728000e+14 |
| 5 | 4.320000e+14 |
| 10 | 8.640000e+14 |
| 25 | 2.160000e+15 |
| 50 | 4.320000e+15 |
| 100 | 8.640000e+15 |
| 250 | 2.160000e+16 |
| 500 | 4.320000e+16 |
| 1,000 | 8.640000e+16 |
Common values
| day | nanosecond | |
|---|---|---|
| Blink of an eye | 0.00000347 day | 300,000,000 nanosecond |
| Average pop song | 0.00243056 day | 2.100000e+11 nanosecond |
| Feature film | 0.08333333 day | 7.200000e+12 nanosecond |
| One work day (8 hrs) | 0.33333333 day | 2.880000e+13 nanosecond |
| One calendar year | 365 day | 3.153600e+16 nanosecond |
Available Time units
More day conversions
- Convert day to second
- Convert day to minute
- Convert day to hour
- Convert day to week
- Convert day to year (365 d)
- Convert day to millisecond
- Convert day to microsecond
- Convert day to nanosecond
- Convert day to century (100 yr)
Assumption: year is defined as 365 days and century values are approximate.