What is millisecond?

A millisecond is a unit of time equal to one thousandth of a second. It is used in computing, networking, audio and video processing, and measuring reaction times and signal latencies.

Real-world uses

Milliseconds are critical in computing for measuring network latency (ping times), database query performance, and real-time system response. Financial trading platforms measure order execution in milliseconds, and human reaction time averages about 250 ms.

History

The millisecond became a practical unit with the invention of precise mechanical chronographs in the 19th century. Its importance exploded with electronic computing, where operations occur in millisecond and sub-millisecond timescales.

Common mistakes

Confusing milliseconds with microseconds in performance profiling—they differ by a factor of 1,000. Also, assuming human perception cannot detect millisecond differences, when in fact audio delays above 10 ms are perceptible.

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).

When is this conversion used?

Converting millisecond to day is useful in the time domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 millisecond = 1.157407e-08 day

1 day = 86,400 second

How to convert millisecond to day

To convert millisecond to day, multiply the value by 1.157407e-08.

To convert day back to millisecond, multiply by 86,400,000.

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: millisecond to day

millisecondday
0.11.157407e-09
0.55.787037e-09
11.157407e-08
22.314815e-08
55.787037e-08
101.157407e-07
252.893519e-07
505.787037e-07
1000.00000116
2500.00000289
5000.00000579
1,0000.00001157

Common values

millisecondday
Blink of an eye300 millisecond0.00000347 day
Average pop song210,000 millisecond0.00243056 day
Feature film7,200,000 millisecond0.08333333 day
One work day (8 hrs)28,800,000 millisecond0.33333333 day
One calendar year3.153600e+10 millisecond365 day