Millisecond to Sidereal Day Converter

Convert milliseconds to sidereal days with our free online time converter.

Quick Answer

1 Millisecond = 1.160576e-8 sidereal days

Formula: Millisecond × conversion factor = Sidereal Day

Use the calculator below for instant, accurate conversions.

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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.

Last verified: December 2025|Reviewed by: Sam Mathew, Software Engineer

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How to Use the Millisecond to Sidereal Day Calculator:

Enter the value you want to convert in the 'From' field (Millisecond).
The converted value in Sidereal Day 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 Millisecond to Sidereal Day: Step-by-Step Guide

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

Formula:

1 Millisecond = 1.1606e-8 sidereal days

Example Calculation:

Convert 60 milliseconds: 60 × 1.1606e-8 = 6.9635e-7 sidereal days

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.

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What is a Millisecond and a Sidereal Day?

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

What Is a Sidereal Day?

A sidereal day is the time required for Earth to complete one full rotation (360 degrees) on its axis relative to the fixed background stars.

Precise value: 1 sidereal day = 86,164.0905 seconds (mean sidereal day) = 23 hours, 56 minutes, 4.0905 seconds

Sidereal vs. Solar Day

Sidereal day (stellar reference):

Earth's rotation relative to distant stars
Duration: 23h 56m 4.091s
Used by astronomers for telescope pointing

Solar day (Sun reference):

Earth's rotation relative to the Sun
Duration: 24h 00m 00s (mean solar day)
Used for civil timekeeping (clocks, calendars)

The difference: ~3 minutes 56 seconds

Why Are They Different?

The sidereal-solar day difference arises from Earth's orbital motion around the Sun:

Start position: Earth completes one full 360° rotation relative to stars (1 sidereal day)
Orbital motion: During that rotation, Earth has moved ~1° along its orbit around the Sun
Extra rotation needed: Earth must rotate an additional ~1° (~4 minutes) to bring the Sun back to the same position in the sky
Result: Solar day = sidereal day + ~4 minutes

Analogy: Imagine walking around a merry-go-round while it spins. If you walk one full circle relative to the surrounding park (sidereal), you'll need to walk a bit farther to return to the same position relative to the merry-go-round center (solar).

One Extra Day Per Year

A surprising consequence: There is one more sidereal day than solar day in a year!

Solar year: 365.242199 solar days
Sidereal year: 365.256363 sidereal days
Extra sidereal days: 366.256363 - 365.242199 ≈ 1 extra day

Why? Earth makes 366.25 full rotations relative to the stars during one orbit, but we only experience 365.25 sunrises because we're moving around the Sun.

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

History of the Millisecond and Sidereal Day

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.

Ancient Observations (2000-300 BCE)

Babylonian astronomy (circa 2000-1500 BCE):

Babylonian astronomers tracked stellar positions for astrological and calendrical purposes
Noticed stars rose earlier each night relative to the Sun's position
Created star catalogs showing this gradual eastward drift

Greek astronomy (circa 600-300 BCE):

Thales of Miletus (624-546 BCE): Used stellar observations for navigation
Meton of Athens (432 BCE): Discovered the 19-year Metonic cycle, reconciling lunar months with solar years
Recognized that stellar year differed from seasonal year

Hipparchus and Precession (150 BCE)

Hipparchus of Nicaea (circa 190-120 BCE), one of history's greatest astronomers:

Discovery: By comparing ancient Babylonian star catalogs with his own observations, Hipparchus discovered precession of the equinoxes—the slow westward drift of the vernal equinox against the stellar background

Sidereal measurements: To detect this subtle effect (1 degree per 72 years), Hipparchus needed precise sidereal positions, implicitly understanding the sidereal day concept

Legacy: His work established the difference between:

Sidereal year: One orbit relative to stars (365.256363 days)
Tropical year: One cycle of seasons (365.242199 days)

The ~20-minute difference between these years arises from precession.

Ptolemy's Almagest (150 CE)

Claudius Ptolemy compiled Greek astronomical knowledge in the Almagest, including:

Star catalogs with sidereal positions
Mathematical models for predicting stellar rising times
Understanding that stars complete one full circuit of the sky slightly faster than the Sun

Though Ptolemy's geocentric model was wrong, his sidereal observations were accurate and useful for centuries.

Islamic Golden Age (800-1400 CE)

Islamic astronomers refined sidereal timekeeping:

Al-Battani (850-929 CE):

Measured the tropical year to high precision
Created improved star catalogs using sidereal positions

Ulugh Beg (1394-1449 CE):

Built the Samarkand Observatory with advanced instruments
Produced star catalogs accurate to ~1 arcminute using sidereal measurements

Copernican Revolution (1543)

Nicolaus Copernicus (De revolutionibus orbium coelestium, 1543):

Heliocentric model: Placing the Sun (not Earth) at the center explained the sidereal-solar day difference:

Earth rotates on its axis (sidereal day)
Earth orbits the Sun (creating solar day difference)
The 4-minute discrepancy results from Earth's ~1° daily orbital motion

This was strong evidence for heliocentrism, though it took decades for acceptance.

Kepler's Laws (1609-1619)

Johannes Kepler formulated laws of planetary motion using sidereal periods:

Third Law: The square of a planet's orbital period is proportional to the cube of its orbit's semi-major axis

Application: Calculating planetary positions required precise sidereal reference frames, not solar time

Rise of Telescopic Astronomy (1600s-1700s)

Galileo Galilei (1609):

Telescopic observations required tracking celestial objects as they moved across the sky
Sidereal time became essential for predicting when objects would be visible

Royal Observatory, Greenwich (1675):

Founded by King Charles II with John Flamsteed as first Astronomer Royal
Developed accurate sidereal clocks to time stellar transits
Greenwich Mean Sidereal Time (GMST) became the astronomical standard

Paris Observatory (1667):

French astronomers developed precision pendulum clocks for sidereal timekeeping
Cassini family produced detailed planetary observations using sidereal coordinates

Precision Timekeeping (1800s)

19th century: Mechanical sidereal clocks achieved second-level accuracy:

Sidereal clock design: Modified to tick 366.2422/365.2422 times faster than solar clocks (accounting for the extra sidereal day per year)

Observatory operations: Major observatories (Greenwich, Paris, Harvard, Lick, Yerkes) used sidereal clocks as primary timekeeping for scheduling observations

Photography: Long-exposure astrophotography required tracking objects at the sidereal rate to prevent star trailing

IAU Standardization (1900s)

International Astronomical Union (IAU) formalized definitions:

Mean sidereal day: 86,164.0905 seconds (exactly, by definition)

Greenwich Mean Sidereal Time (GMST): Standard sidereal time referenced to Greenwich meridian

Vernal equinox reference: Traditional sidereal time measures Earth's rotation relative to the vernal equinox (intersection of celestial equator and ecliptic)

Modern Era: ICRF (1997-Present)

International Celestial Reference Frame (ICRF):

Problem: The vernal equinox shifts due to precession, making it an imperfect reference

Solution: ICRF uses ~300 distant quasars (billions of light-years away) as fixed reference points

Accuracy: Defines celestial positions to milliarcsecond precision

Atomic time: Sidereal time is now calculated from International Atomic Time (TAI) and Earth orientation parameters measured by Very Long Baseline Interferometry (VLBI)

Modern sidereal clocks: Digital, GPS-synchronized, automatically updated for Earth rotation variations

Common Uses and Applications: milliseconds vs sidereal days

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

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).

When to Use sidereal days

1. Telescope Pointing and Tracking

Professional observatories use sidereal time to point telescopes:

Right Ascension (RA): Celestial equivalent of longitude, measured in hours of sidereal time (0h to 24h)

Local Sidereal Time (LST): The current RA crossing the meridian

Pointing formula: If LST = 18h 30m, objects with RA ≈ 18h 30m are currently at their highest point (zenith)

Tracking rate: Telescope motors rotate at the sidereal rate (1 rotation per 23h 56m 4s) to follow stars across the sky as Earth rotates

Example:

Vega: RA = 18h 37m
When LST = 18:37, Vega crosses the meridian (highest in sky)
Observer can plan observations when object will be optimally placed

2. Astrophotography

Long-exposure astrophotography requires tracking at the sidereal rate:

Problem: Earth's rotation makes stars trail across the image during long exposures

Solution: Equatorial mounts with sidereal drive motors:

Rotate at exactly 1 revolution per sidereal day
Keep stars fixed in the camera's field of view
Enables exposures of minutes to hours without star trailing

Adjustment: Solar rate ≠ sidereal rate; photographers must use sidereal tracking for stars, solar tracking for Sun/Moon

3. Satellite Orbit Planning

Satellite engineers use sidereal time for orbit design:

Sun-synchronous orbits: Satellites that always cross the equator at the same local solar time

Orbital period is chosen to precess at the solar rate, not sidereal rate

Geosynchronous orbits: Satellites that hover over one point on Earth

Orbital period = 1 sidereal day (23h 56m 4s)
NOT 24 hours! Common misconception.

Molniya orbits: High-eccentricity orbits with period = 0.5 sidereal days for optimal high-latitude coverage

4. Very Long Baseline Interferometry (VLBI)

Radio astronomers use VLBI to achieve ultra-high resolution:

Technique: Combine signals from radio telescopes across continents

Timing requirement: Sidereal time must be synchronized to nanosecond precision across all telescopes

Result: VLBI can resolve features 1,000 times smaller than Hubble Space Telescope (angular resolution ~0.0001 arcseconds)

Application: Measures Earth's rotation variations by observing quasars at precise sidereal times

5. Navigation and Geodesy

Sidereal time is used for precise Earth orientation measurements:

Earth Orientation Parameters (EOPs):

Polar motion (wobble of Earth's axis)
UT1 (Earth rotation angle, related to Greenwich sidereal time)
Length of day variations

GPS accuracy: GPS navigation requires knowing Earth's orientation to ~1 meter precision, necessitating sidereal time corrections

Tidal forces: Moon and Sun create tidal bulges that affect Earth's rotation, causing sidereal day variations at the millisecond level

6. Space Navigation

Spacecraft use sidereal reference frames:

Star trackers: Autonomous spacecraft orientation using star patterns

Compare observed stellar positions with catalog
Catalog uses sidereal coordinates (RA/Dec)

Interplanetary navigation: Voyager, New Horizons, and other deep-space probes navigate using sidereal reference frames (ICRF)

Mars rovers: Use Martian sidereal time ("sols") for mission planning

1 Mars sol = 24h 39m 35s (Mars rotates slower than Earth)

7. Amateur Astronomy

Amateur astronomers use sidereal time for planning:

Planispheres: Rotating star charts that show which constellations are visible at any given sidereal time and date

Computerized telescopes: GoTo mounts require accurate sidereal time for automatic star finding

Observation logs: Record sidereal time of observations for repeatability

Additional Unit Information

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.

About Sidereal Day (sidereal day)

How long is a sidereal day in standard time?

Answer: 23 hours, 56 minutes, 4.091 seconds (or 86,164.091 seconds)

This is the time for Earth to rotate exactly 360 degrees relative to distant stars.

Precise value: 1 mean sidereal day = 86,164.0905 seconds

Comparison to solar day:

Solar day: 86,400 seconds (24 hours)
Sidereal day: 86,164.091 seconds
Difference: ~236 seconds shorter (~3 min 56 sec)

Important: This is the mean sidereal day. Earth's actual rotation rate varies slightly (milliseconds) due to tidal forces, atmospheric winds, earthquakes, and core-mantle coupling.

Why is a sidereal day shorter than a solar day?

Answer: Because Earth orbits the Sun while rotating—requiring extra rotation to bring the Sun back to the same sky position

Step-by-step explanation:

Starting point: The Sun is directly overhead (noon)
One sidereal day later (23h 56m 4s): Earth has rotated exactly 360° relative to stars
- But Earth has also moved ~1° along its orbit around the Sun
- The Sun now appears slightly east of overhead
Extra rotation needed: Earth must rotate an additional ~1° (taking ~4 minutes) to bring the Sun back overhead
Result: Solar day (noon to noon) = sidereal day + ~4 minutes = 24 hours

Orbital motion causes the difference: Earth moves ~1°/day along its 365-day orbit (360°/365 ≈ 0.986°/day). This ~1° requires ~4 minutes of extra rotation (24 hours / 360° ≈ 4 min/degree).

Consequence: Stars rise ~4 minutes earlier each night relative to solar time, shifting ~2 hours per month, completing a full cycle annually.

Is sidereal time the same everywhere on Earth?

Answer: No—Local Sidereal Time (LST) depends on longitude, just like solar time zones

Key concepts:

Local Sidereal Time (LST): The Right Ascension (RA) currently crossing your local meridian

Different at every longitude
Changes by 4 minutes for every 1° of longitude

Greenwich Mean Sidereal Time (GMST): Sidereal time at 0° longitude (Greenwich meridian)

Global reference point, like GMT/UTC for solar time

Conversion: LST = GMST ± longitude offset

Positive (add) for east longitudes
Negative (subtract) for west longitudes

Example:

GMST = 12:00
New York (74°W): LST = 12:00 - (74°/15) = 07:04
Tokyo (139.75°E): LST = 12:00 + (139.75°/15) = 21:19

Duration is universal: A sidereal day (23h 56m 4s) is the same length everywhere—only the current sidereal time differs by location.

Do geosynchronous satellites orbit every 24 hours or 23h 56m?

Answer: 23h 56m 4s (one sidereal day)—NOT 24 hours!

This is one of the most common misconceptions about satellites.

The physics: For a satellite to remain above the same point on Earth's surface, it must orbit at Earth's rotational rate relative to the stars, not relative to the Sun.

Why sidereal?

Earth rotates 360° in one sidereal day (23h 56m 4s)
Satellite must complete 360° orbit in the same time
This keeps satellite and ground point aligned relative to the stellar background

If orbit were 24 hours: The satellite would complete one orbit in one solar day, but Earth would have rotated 360° + ~1° (relative to stars) during that time. The satellite would drift ~1° westward per day, completing a full circuit westward in one year!

Geostationary orbit specifics:

Altitude: 35,786 km above equator
Period: 23h 56m 4.091s (1 sidereal day)
Velocity: 3.075 km/s

Common examples: Communications satellites, weather satellites (GOES, Meteosat)

How many sidereal days are in a year?

Answer: Approximately 366.25 sidereal days—one MORE than the number of solar days!

Precise values:

Tropical year (season to season): 365.242199 mean solar days
Sidereal year (star to star): 365.256363 mean solar days
Sidereal days in tropical year: 366.242199 sidereal days

One extra day: There is exactly one more complete rotation relative to stars than we experience sunrises.

Why?

Earth makes 366.25 complete 360° rotations relative to stars per year
But we experience only 365.25 sunrises because we orbit the Sun
One rotation is "used up" by Earth's orbit around the Sun

Thought experiment: Stand on a rotating platform while walking around a lamp. If you walk one complete circle around the lamp (1 orbit), you'll have spun around 2 complete times relative to the room walls (2 rotations): 1 from walking the circle + 1 from the platform spinning.

Can I use a regular clock to tell sidereal time?

Answer: Not directly—sidereal clocks run about 4 minutes faster per day than solar clocks

Clock rate difference:

Solar clock: Completes 24 hours in 1 solar day (86,400 seconds)
Sidereal clock: Completes 24 sidereal hours in 1 sidereal day (86,164.091 seconds)
Rate ratio: 1.00273791 (sidereal clock ticks ~0.27% faster)

Practical result: After one solar day:

Solar clock reads: 24:00
Sidereal clock reads: 24:03:56 (3 min 56 sec ahead)

Modern solutions:

Sidereal clock apps: Smartphone apps calculate LST from GPS location and atomic time
Planetarium software: Stellarium, SkySafari show current LST
Observatory systems: Automated telescopes use GPS-synchronized sidereal clocks

Historical: Mechanical sidereal clocks used gear ratios of 366.2422/365.2422 to run at the correct rate

You can calculate: LST from solar time using formulas, but it's complex (requires Julian Date, orbital mechanics)

Why do astronomers use sidereal time instead of solar time?

Answer: Because celestial objects return to the same position every sidereal day, not solar day

Astronomical reason:

Stars and galaxies are so distant they appear "fixed" in the sky:

A star at RA = 18h 30m crosses the meridian at LST = 18:30 every sidereal day
Predictable, repeatable observations

If using solar time: Stars would cross the meridian ~4 minutes earlier each night, requiring daily recalculation of observation windows

Practical advantages:

1. Simple telescope pointing:

Object's RA directly tells you when it's overhead (LST = RA)
No date-dependent calculations needed

2. Repeatable observations:

"Observe target at LST = 22:00" means the same sky position regardless of date

3. Right Ascension coordinate system:

Celestial longitude measured in hours/minutes of sidereal time (0h to 24h)
Aligns naturally with Earth's rotation

4. Tracking rate:

Telescopes track at sidereal rate (1 revolution per 23h 56m 4s)
Keeps stars fixed in the field of view

Historical: Before computers, sidereal time made astronomical calculations much simpler

What is the difference between a sidereal day and a sidereal year?

Answer: A sidereal day measures Earth's rotation; a sidereal year measures Earth's orbit

Sidereal Day:

Definition: Time for Earth to rotate 360° on its axis relative to stars
Duration: 23h 56m 4.091s (86,164.091 seconds)
Reference: Distant "fixed" stars
Use: Telescope tracking, astronomy observations

Sidereal Year:

Definition: Time for Earth to orbit 360° around the Sun relative to stars
Duration: 365.256363 days (365d 6h 9m 9s)
Reference: Position relative to distant stars (not seasons)
Use: Orbital mechanics, planetary astronomy

Key distinction:

Day = rotation (Earth spinning)
Year = revolution (Earth orbiting)

Tropical vs. Sidereal Year:

Tropical year: 365.242199 days (season to season, used for calendars)
Sidereal year: 365.256363 days (star to star)
Difference: ~20 minutes, caused by precession of Earth's axis

The 20-minute precession effect: Earth's axis wobbles with a 26,000-year period, causing the vernal equinox to shift ~50 arcseconds/year westward against the stellar background. This makes the tropical year (equinox to equinox) slightly shorter than the sidereal year (star to star).

Does the Moon have a sidereal day?

Answer: Yes—the Moon's sidereal day is 27.322 Earth days, but it's tidally locked to Earth

Moon's sidereal rotation: Time for Moon to rotate 360° relative to stars = 27.322 days

Tidal locking: The Moon's rotation period equals its orbital period around Earth (both 27.322 days)

Consequence: The same face of the Moon always points toward Earth

We only see ~59% of Moon's surface from Earth (libration allows slight wobbling)
The "far side" never faces Earth

Moon's "solar day" (lunar day):

Time from sunrise to sunrise on Moon's surface: 29.531 Earth days
Different from Moon's sidereal day (27.322 days) for the same reason Earth's solar day differs from sidereal day
Moon orbits Earth while rotating, requiring extra rotation to bring the Sun back to the same position

Lunar missions: Apollo missions and rovers used "lunar days" for mission planning—each day-night cycle lasts ~29.5 Earth days (2 weeks daylight, 2 weeks night)

How is sidereal time measured today?

Answer: Using atomic clocks, GPS, and Very Long Baseline Interferometry (VLBI) observations of distant quasars

Modern measurement system:

1. International Atomic Time (TAI):

Network of ~450 atomic clocks worldwide
Defines the second with nanosecond precision
Provides base timescale

2. UT1 (Universal Time):

Earth's rotation angle (actual rotation measured continuously)
Monitored by VLBI observations of quasars

3. VLBI technique:

Radio telescopes across continents simultaneously observe distant quasars
Time differences reveal Earth's exact orientation
Accuracy: ~0.1 milliseconds (0.005 arcseconds rotation)

4. ICRF (International Celestial Reference Frame):

Defines "fixed" stellar background using ~300 quasars billions of light-years away
Replaces older vernal equinox reference (which shifts due to precession)

5. GPS satellites:

Amateur astronomers and observatories use GPS for accurate time and location
Software calculates LST from UTC, GPS coordinates, and Earth orientation parameters

Calculation chain:

Atomic clocks provide UTC
Earth orientation parameters (EOP) give UT1
Sidereal time formulas convert UT1 → GMST
Longitude correction gives LST

Accuracy: Modern systems know Earth's orientation to ~1 centimeter (as a position on Earth's surface), requiring sidereal time precision of ~0.001 seconds

Why so complex? Earth's rotation is not uniform:

Tidal forces (Moon/Sun) slow rotation by ~2.3 ms/century
Atmospheric winds cause daily variations (milliseconds)
Earthquakes can shift rotation by microseconds
Core-mantle coupling affects long-term drift

Continuous monitoring ensures astronomical observations remain accurate.

Will sidereal time ever be replaced by something else?

Answer: Unlikely—it's fundamental to astronomy, tied directly to Earth's rotation and stellar positions

Why sidereal time persists:

1. Physical basis: Directly tied to Earth's rotation relative to the universe

Not an arbitrary human convention like time zones
Essential for understanding celestial mechanics

2. Coordinate system: Right Ascension (celestial longitude) is measured in sidereal hours

All star catalogs, telescope systems, and astronomical databases use RA/Dec
Replacing it would require re-cataloging billions of objects

3. Telescope tracking: All telescope mounts track at the sidereal rate

Mechanically and electronically built into equipment
Solar tracking is used only for Sun/Moon

4. International standards: IAU, observatories, space agencies globally use sidereal time

Standardized formulas and software

5. No alternative needed: Sidereal time does its job perfectly for astronomy

Evolution, not replacement:

Old reference: Vernal equinox (shifts due to precession)
New reference: ICRF quasars (effectively fixed)
Future: Increasingly precise atomic timescales and Earth rotation monitoring

Non-astronomical contexts: Civil society will continue using solar time (UTC) for daily life—there's no need for most people to know sidereal time

Conclusion: Sidereal time is here to stay as long as humans do astronomy from Earth. Even space-based observatories use sidereal coordinate systems for consistency with ground observations.

Conversion Table: Millisecond to Sidereal Day

Millisecond (ms)	Sidereal Day (sidereal day)
0.5	0
1	0
1.5	0
2	0
5	0
10	0
25	0
50	0
100	0
250	0
500	0
1,000	0

How do I convert Millisecond to Sidereal Day?

To convert Millisecond to Sidereal Day, enter the value in Millisecond in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our time converter page to convert between other units in this category.

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What is the conversion factor from Millisecond to Sidereal Day?

The conversion factor depends on the specific relationship between Millisecond and Sidereal Day. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.

Can I convert Sidereal Day back to Millisecond?

Yes! You can easily convert Sidereal Day back to Millisecond by using the swap button (⇌) in the calculator above, or by visiting our Sidereal Day to Millisecond converter page. You can also explore other time conversions on our category page.

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What are common uses for Millisecond and Sidereal Day?

Millisecond and Sidereal Day are both standard units used in time measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our time converter for more conversion options.

For more time conversion questions, visit our FAQ page or explore our conversion guides.

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