Day to Millisecond Conversion Calculator: Free Online Tool

Convert days to milliseconds with our free online time converter.

From:

Day

To:

Millisecond

How to Use the Calculator:

Enter the value you want to convert in the 'From' field (Day).
The converted value in Millisecond will appear automatically in the 'To' field.
Use the dropdown menus to select different units within the Time category.
Click the swap button (⇌) to reverse the conversion direction.

How to Convert Day to Millisecond

Converting Day to Millisecond involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Day = 8.6400e+7 milliseconds

Example Calculation:

Convert 60 days: 60 × 8.6400e+7 = 5.1840e+9 milliseconds

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Day and a Millisecond?

A day is a unit of time typically defined as 24 hours, which is equivalent to 1,440 minutes or 86,400 seconds. It roughly corresponds to one full rotation of the Earth on its axis relative to the Sun (a solar day).

A millisecond is a unit of time equal to one-thousandth (1/1,000) of a second.

Note: The Day is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Millisecond belongs to the imperial/US customary system.

History of the Day and Millisecond

The concept of a day as a fundamental cycle of light and darkness is ancient. The division into 24 hours developed over time, notably influenced by the Egyptians. While the solar day (time between two successive solar noons) varies slightly throughout the year, the standard mean solar day of 86,400 SI seconds is used for civil timekeeping.

The millisecond is derived from the SI base unit, the second, using the metric prefix 'milli-', indicating a factor of 10⁻³. Its common usage grew with the need for finer time measurements in science and technology, particularly in fields like computing and electronics.

Common Uses for days and milliseconds

Explore the typical applications for both Day (imperial/US) and Millisecond (imperial/US) to understand their common contexts.

Common Uses for days

Civil Timekeeping: The primary unit for organizing daily life, calendars, schedules, and dates.
Astronomy: Used to measure rotational periods of planets and other celestial bodies (though the definition might differ, e.g., sidereal day).
Duration: Measuring the length of events, projects, trips, or lifespans that span multiple hours.
Biology: Studying circadian rhythms (biological processes that follow a roughly 24-hour cycle).
Work & Rest: Structuring periods of work, leisure, and sleep.

Common Uses for milliseconds

Computing: Measuring network latency (ping times), hard drive seek times, human reaction times in psychological tests, frame duration in video (e.g., 60 fps is ~16.7 ms per frame).
Audio: Measuring delays and processing times in audio signals.
Sports: Timing in races where differences are extremely small (e.g., swimming, track and field).
Science: Measuring short-duration events, such as the firing of a neuron or rapid chemical processes.
User Interface: Often used as a target for response times in interactive systems (e.g., aiming for under 100 ms for a feeling of instant response).

Frequently Asked Questions

Questions About Day (d)

How many hours are in a day?

There are typically 24 hours in a standard civil day.

How many seconds are in a day?

There are 86,400 seconds in a standard 24-hour day (24 hours * 60 minutes/hour * 60 seconds/minute).

Is every day exactly 24 hours long?

The apparent solar day (time from one noon to the next) varies slightly due to the Earth's elliptical orbit and axial tilt. The mean solar day, used for clocks, averages this out to 24 hours. Leap seconds are occasionally added to keep clock time aligned with the Earth's rotation.

What's the difference between a solar day and a sidereal day?

A solar day is based on the Sun's position (approx. 24 hours). A sidereal day is based on the Earth's rotation relative to distant stars (approx. 23 hours, 56 minutes, 4 seconds).

About Millisecond (ms)

How many milliseconds are in one second?

There are 1,000 milliseconds in a second.

How many milliseconds are in one minute?

There are 60,000 milliseconds in a minute (1000 ms/s * 60 s/min).

Is a millisecond a long time for a computer?

In computing terms, a millisecond can be quite long. Processors perform millions of operations in a millisecond. Network latency is often measured in tens or hundreds of milliseconds.

Conversion Table: Day to Millisecond

Day (d)	Millisecond (ms)
1	86,400,000
5	432,000,000
10	864,000,000
25	2,160,000,000
50	4,320,000,000
100	8,640,000,000
500	43,200,000,000
1,000	86,400,000,000

All Time Conversions

Second to Minute Second to Hour Second to Day Second to Week Second to Month Second to Year Second to Millisecond Second to Microsecond Second to Nanosecond Second to Decade Second to Century Second to Millennium Second to Fortnight Second to Planck Time Second to Shake Second to Sidereal Day Second to Sidereal Year Minute to Second Minute to Hour Minute to Day Minute to Week Minute to Month Minute to Year Minute to Millisecond Minute to Microsecond Minute to Nanosecond Minute to Decade Minute to Century Minute to Millennium Minute to Fortnight Minute to Planck Time Minute to Shake Minute to Sidereal Day Minute to Sidereal Year Hour to Second Hour to Minute Hour to Day Hour to Week Hour to Month Hour to Year Hour to Millisecond Hour to Microsecond Hour to Nanosecond Hour to Decade Hour to Century Hour to Millennium Hour to Fortnight Hour to Planck Time Hour to Shake Hour to Sidereal Day Hour to Sidereal Year Day to Second Day to Minute Day to Hour Day to Week Day to Month Day to Year Day to Microsecond Day to Nanosecond Day to Decade Day to Century Day to Millennium Day to Fortnight Day to Planck Time Day to Shake Day to Sidereal Day Day to Sidereal Year Week to Second Week to Minute Week to Hour Week to Day Week to Month Week to Year Week to Millisecond Week to Microsecond Week to Nanosecond Week to Decade Week to Century Week to Millennium Week to Fortnight Week to Planck Time Week to Shake Week to Sidereal Day Week to Sidereal Year Month to Second Month to Minute Month to Hour Month to Day Month to Week Month to Year Month to Millisecond Month to Microsecond Month to Nanosecond Month to Decade Month to Century Month to Millennium Month to Fortnight Month to Planck Time Month to Shake Month to Sidereal Day Month to Sidereal Year Year to Second Year to Minute Year to Hour Year to Day Year to Week Year to Month Year to Millisecond Year to Microsecond Year to Nanosecond Year to Decade Year to Century Year to Millennium Year to Fortnight Year to Planck Time Year to Shake Year to Sidereal Day Year to Sidereal Year Millisecond to Second Millisecond to Minute