Week to Sidereal Day Conversion Calculator: Free Online Tool

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

From:

Week

To:

Sidereal Day

How to Use the Calculator:

Enter the value you want to convert in the 'From' field (Week).
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 Week to Sidereal Day

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

Formula:

1 Week = 7.019165 sidereal days

Example Calculation:

Convert 60 weeks: 60 × 7.019165 = 421.1499 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.

What is a Week and a Sidereal Day?

A week is a unit of time equal to seven days. It is not an SI unit but is widely used as a convenient cycle for organizing activities longer than a day but shorter than a month.

A sidereal day is the time it takes for the Earth to complete one full rotation on its axis relative to the distant, fixed stars. It is approximately 23 hours, 56 minutes, and 4.091 seconds long. This is slightly shorter than the 24-hour solar day, which is based on the Earth's rotation relative to the Sun.

Note: The Week 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 Week and Sidereal Day

The seven-day week has origins in ancient Babylonian astronomy, linked to the seven classical celestial bodies visible to the naked eye (Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn). This system was adopted by the Jews and later spread through Christianity and Islam. While other cultures have used different week lengths throughout history, the seven-day week became dominant globally, particularly with the adoption of the Gregorian calendar.

The concept of the sidereal day originates from ancient astronomy. Early astronomers observed that the stars appeared to return to the same position in the sky slightly earlier each day when measured against the Sun's cycle. This discrepancy led to the understanding that the Earth's rotation period relative to the background stars (sidereal) was different from its rotation period relative to the Sun (solar). Accurate measurement of the sidereal day became crucial for precise astronomical observations and timekeeping, allowing astronomers to predict the positions of celestial objects.

Common Uses for weeks and sidereal days

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

Common Uses for weeks

Scheduling: Organizing work schedules (work week vs. weekend), school schedules, social events, and appointments.
Calendars: The fundamental structure block in most modern calendars.
Planning: Used for short-term planning of tasks, projects, holidays, and recurring events.
Cycles: Measuring durations like project phases, rental periods, medication schedules, or publication frequencies (weekly magazines).
Cultural/Religious Observance: Many cultures and religions observe specific days of the week for rest, worship, or specific activities (e.g., Sabbath, Sunday).

Common Uses for sidereal days

The sidereal day and sidereal time are primarily used in:

Astronomy: To point telescopes accurately at celestial objects. Astronomical observatories use sidereal clocks to know when specific stars or galaxies will be overhead or in a particular position for observation.
Astrophysics: For calculations involving celestial mechanics and the timing of astronomical events.
Satellite Tracking: Used in calculations for positioning and tracking artificial satellites in Earth orbit.
Geodesy: For precise measurements related to the Earth's rotation and orientation in space.

It is generally not used for civil timekeeping, which relies on the solar day.

Frequently Asked Questions

Questions About Week (wk)

How many days are in a week?

There are 7 days in a week.

How many hours are in a week?

There are 168 hours in a week (7 days * 24 hours/day).

Is the week an official SI unit?

No, the week is not part of the International System of Units (SI). The base unit of time is the second.

Where did the seven-day week come from?

It is believed to originate with the ancient Babylonians, who associated the number seven with the seven visible celestial bodies (Sun, Moon, and five planets).

About Sidereal Day (sidereal day)

How long is a sidereal day in standard time?

A mean sidereal day is approximately 23 hours, 56 minutes, and 4.091 seconds (or about 86,164.091 seconds). This is roughly 3 minutes and 56 seconds shorter than a standard 24-hour solar day.

Why is a sidereal day shorter than a solar day?

A sidereal day measures Earth's rotation relative to distant stars. A solar day measures rotation relative to the Sun. As the Earth rotates, it also orbits the Sun. After one full rotation relative to the stars (one sidereal day), the Earth has moved slightly along its orbit. It needs to rotate a little bit further (about 1 degree, taking nearly 4 minutes) to bring the Sun back to the same apparent position in the sky (completing a solar day).

Is sidereal time the same everywhere on Earth?

No, just like solar time, local sidereal time depends on your longitude. At any given moment, different locations on Earth will have different local sidereal times, corresponding to which part of the celestial sphere is currently crossing their local meridian. However, the duration of a sidereal day is the same everywhere.

Conversion Table: Week to Sidereal Day

Week (wk)	Sidereal Day (sidereal day)
1	7.019
5	35.096
10	70.192
25	175.479
50	350.958
100	701.917
500	3,509.583
1,000	7,019.165

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 Millisecond 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 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