What is a time unit converter?

A time unit converter is a tool that transforms measurements between different units of time, from femtoseconds to millennia. It's essential for scientific calculations, project planning, travel scheduling, and understanding historical timescales.

What is the standard SI unit of time?

The second (s) is the SI base unit of time. It's defined by the radiation cycles of cesium-133 atoms—specifically, 9,192,631,770 cycles equal one second. This atomic definition provides incredible precision, accurate to within one second in millions of years.

Where are time conversions important?

Time conversions are essential in project management (days to hours), scientific research (milliseconds to nanoseconds), astronomy (years to centuries), computing (seconds to milliseconds), travel planning (time zones), and historical research (years to decades).

Why are different time units used?

Different scales require different units for practical measurement. We use nanoseconds for computer operations, seconds for human reflexes, hours for daily activities, and years for life events. Using appropriate units makes numbers more manageable and meaningful.

How many seconds are in a day?

There are exactly 86,400 seconds in a day (24 hours × 60 minutes × 60 seconds). This is the basis for many time calculations. A week has 604,800 seconds, and a common year has 31,536,000 seconds.

What is the difference between a common year and a leap year?

A common year has 365 days (31,536,000 seconds), while a leap year has 366 days (31,622,400 seconds). Leap years occur every 4 years (with exceptions for century years) to keep our calendar aligned with Earth's orbit around the sun.

What is a synodic month?

A synodic month (29.53 days) is the time between identical moon phases, like full moon to full moon. It's different from a calendar month and was the basis for many ancient calendars. Twelve synodic months equal about 354 days, which is why lunar calendars drift relative to the seasons.

How small can time measurements get?

Modern physics measures time in incredibly small units: milliseconds (10⁻³), microseconds (10⁻⁶), nanoseconds (10⁻⁹), picoseconds (10⁻¹²), femtoseconds (10⁻¹⁵), and even smaller. The shortest measured time is about 247 zeptoseconds (10⁻²¹ seconds).

A fortnight equals 14 days or 2 weeks. The term comes from 'fourteen nights' and is still commonly used in British English and some Commonwealth countries for scheduling and payroll periods.

How is a year defined scientifically?

There are several 'year' definitions: the tropical year (365.24219 days) measures equinox to equinox, the Julian year (365.25 days) is used in astronomy, and the Gregorian calendar year averages 365.2425 days. Our calendar uses the Gregorian year with leap year rules.

Time Unit Converter | Rapid Unit Converter

Convert between different time units like days, hours, seconds...etc

Time is one of the seven SI base quantities, measuring the progression of events from past through present to future. From the femtoseconds of chemical reactions to the millennia of geological ages, accurate time conversion is essential in science, technology, and daily life. Our converter handles all standard time units with precision, helping you work across different timescales.

History & Background

Humans have measured time for millennia using sundials, water clocks, and astronomical observations. The second was historically defined as 1/86,400 of a mean solar day. In 1967, the second was redefined using atomic clocks, specifically the vibration of cesium-133 atoms, providing unprecedented accuracy. Today's atomic clocks are so precise they would lose less than one second over 300 million years.

How to Convert

Hours to Seconds

seconds = hours × 3,600

Multiply hours by 3,600 (60 minutes × 60 seconds) to get seconds.

Example: 8 hours × 3,600 = 28,800 seconds

Days to Hours

hours = days × 24

Multiply the number of days by 24 to get hours.

Example: 7 days × 24 = 168 hours

Years to Days

days = years × 365.25

Multiply years by 365.25 to account for leap years.

Example: 10 years × 365.25 = 3,652.5 days

Milliseconds to Seconds

seconds = milliseconds ÷ 1,000

Divide milliseconds by 1,000 to convert to seconds.

Example: 5,000 ms ÷ 1,000 = 5 seconds

Real-World Examples

Work Week

A standard 40-hour work week converted to different time units.

40 hours=144,000 seconds

Human Reaction Time

Average human visual reaction time is about 250 milliseconds.

250 ms=0.25 seconds

Moon Orbit

The Moon completes one orbit around Earth in about 27.3 days (sidereal month).

27.3 days=655.2 hours

Light Nanosecond

Light travels approximately 30 centimeters in one nanosecond.

1 ns=0 seconds

Human Lifespan

The average global human lifespan is approximately 73 years.

73 years=2.3 billion seconds

Olympic Sprint

The 100m world record is 9.58 seconds (Usain Bolt, 2009).

9.58 seconds=9,580 ms

Did You Know?

•The most accurate atomic clocks are so precise they would neither gain nor lose a second in over 300 million years.
•A 'jiffy' is an actual unit of time used in physics, typically defined as 1/60th or 1/100th of a second, though definitions vary by field.
•The shortest time interval ever measured is 247 zeptoseconds—the time it takes a photon to cross a hydrogen molecule.
•Due to time dilation, GPS satellites experience time about 38 microseconds faster per day than clocks on Earth, requiring constant correction.
•The Universe is approximately 13.8 billion years old, while the oldest known rocks on Earth are about 4 billion years old.

Time conversion table

1 s = 3.1709791983764586e-10 C	1 seconds equals 3.1709791983764586e-10 centuries	1 * 3.1709791983764586e-10 = X C
1 s = 0.000011574074074074073 d	1 seconds equals 0.000011574074074074073 days	1 * 0.000011574074074074073 = X d
1 s = 3.1709791983764586e-9 D	1 seconds equals 3.1709791983764586e-9 decades	1 * 3.1709791983764586e-9 = X D
1 s = 999999999999999.9 fs	1 seconds equals 999999999999999.9 femtoseconds	1 * 999999999999999.9 = X fs
1 s = 8.267195767195768e-7 ftn	1 seconds equals 8.267195767195768e-7 fortnights	1 * 8.267195767195768e-7 = X ftn
1 s = 0.0002777777777777778 h	1 seconds equals 0.0002777777777777778 hours	1 * 0.0002777777777777778 = X h
1 s = 1000000 μs	1 seconds equals 1000000 microseconds	1 * 1000000 = X μs
1 s = 3.1709791983764586e-11	1 seconds equals 3.1709791983764586e-11 millenia	1 * 3.1709791983764586e-11 = X
1 s = 1000 ms	1 seconds equals 1000 milliseconds	1 * 1000 = X ms
1 s = 0.016666666666666666 min	1 seconds equals 0.016666666666666666 minutes	1 * 0.016666666666666666 = X min
1 s = 3.8051750380517503e-7 month	1 seconds equals 3.8051750380517503e-7 months (Common)	1 * 3.8051750380517503e-7 = X month
1 s = 3.9193509056233435e-7 month	1 seconds equals 3.9193509056233435e-7 months (Synodic)	1 * 3.9193509056233435e-7 = X month
1 s = 999999999.9999999 ns	1 seconds equals 999999999.9999999 nanoseconds	1 * 999999999.9999999 = X ns
1 s = 1000000000000 ps	1 seconds equals 1000000000000 picoseconds	1 * 1000000000000 = X ps
1 s = 1.2683916793505834e-7	1 seconds equals 1.2683916793505834e-7 quarters (Common)	1 * 1.2683916793505834e-7 = X
1 s = 100000000	1 seconds equals 100000000 shakes	1 * 100000000 = X
1 s = 0.0000016534391534391535	1 seconds equals 0.0000016534391534391535 weeks	1 * 0.0000016534391534391535 = X
1 s = 3.1709791983764586e-8 y	1 seconds equals 3.1709791983764586e-8 years (Common)	1 * 3.1709791983764586e-8 = X y
1 s = 3.168873850681143e-8	1 seconds equals 3.168873850681143e-8 years (Average Gregorian)	1 * 3.168873850681143e-8 = X
1 s = 3.168808781402895e-8	1 seconds equals 3.168808781402895e-8 years (Julian)	1 * 3.168808781402895e-8 = X
1 s = 3.1623153207852664e-8	1 seconds equals 3.1623153207852664e-8 years (Leap)	1 * 3.1623153207852664e-8 = X
1 s = 3.168876540268821e-8	1 seconds equals 3.168876540268821e-8 years (Tropical)	1 * 3.168876540268821e-8 = X

F.A.Q. - Frequently Asked Questions

Time Unit Converter