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Time Unit Converter

Convert between seconds, minutes, hours, days, weeks, months, years, milliseconds, microseconds, nanoseconds, fortnights, decades, centuries, millennia, Planck time, and more. Tick “Advanced Mode” to reveal exotic units like shakes, Svedberg, Callippic cycle, Metonic cycle, kè, jiffy, and Hipparchic cycle.

Enter Time to Convert

Milliseconds, microseconds, nanoseconds, fortnights, decades, centuries, millennia, shakes, Svedberg, Planck time, atomic unit of time, Callippic cycle, Metonic cycle, kè, jiffy, Hipparchic cycle.

Converted Time

Result: –

Scientific Form: –

Grouped Digits: –

Overview

Time units range from the familiar—seconds, minutes, hours, days, weeks, months, years—to far more exotic scales: milliseconds, microseconds, nanoseconds, fortnights, decades, centuries, millennia, and even Planck time (the quantum‐gravity scale). In Advanced Mode, you’ll uncover “shakes” (10⁻⁸ s), “Svedberg” (10⁻¹³ s), the “atomic unit of time” (≈2.4189×10⁻¹⁷ s), “Callippic cycle” (76 years), “Metonic cycle” (19 years), “kè” (Chinese kè = 1/100 day), “jiffy” (light in 1 cm ≈ 3.33564×10⁻¹¹ s), and the “Hipparchic cycle” (304 years). Use this tool to convert any quantity from one unit into another instantly.

Note: “Month” is defined as exactly 30 days (2 592 000 s). “Year” is 365 days (31 536 000 s). Adjust factors in JavaScript if you need calendar‐specific accuracy (e.g., Feb or leap years).

Formula & Methodology

All conversions go through an intermediate “seconds” step:

  1. Convert the input value into seconds using the known factor (unit → seconds).
  2. Convert those seconds into the desired unit using seconds → unit factor.

Below is a complete table of “unit → seconds” factors used internally.

Unit Equivalent in Seconds Definition / Notes
Second (s)1Base SI unit of time.
Millisecond (ms)0.0011 ms = 10⁻³ s.
Microsecond (µs)0.0000011 µs = 10⁻⁶ s.
Nanosecond (ns)0.0000000011 ns = 10⁻⁹ s.
Minute (min)6060 s.
Hour (h)360060 min = 3600 s.
Day (d)8640024 h = 86 400 s.
Week (wk)6048007 d = 604 800 s.
Fortnight (fn)120960014 d = 1 209 600 s.
Month (mo)259200030 d = 2 592 000 s (approx.).
Year (yr)31536000365 d = 31 536 000 s (approx.).
Decade (dec)31536000010 yr = 315 360 000 s.
Century (c)3153600000100 yr = 3 153 600 000 s.
Millennium (mil)315360000001000 yr = 31 536 000 000 s.
Shake0.000000011 shake = 10⁻⁸ s (used in nuclear engineering).
Svedberg0.00000000000011 Svedberg = 10⁻¹³ s (used in ultracentrifugation).
Planck Time (tₚ)5.391247e-44Smallest meaningful time in quantum gravity ≈ 5.391247×10⁻⁴⁴ s.
Atomic Unit of Time (a.u.)2.418884e-171 atomic unit = ħ/Eₕ ≈ 2.418884×10⁻¹⁷ s.
Jiffy3.33564095198152e-11Time light travels 1 cm in vacuum ≈ 3.33564×10⁻¹¹ s.
Callippic Cycle239673600076 yr = 2 396 736 000 s.
Metonic Cycle59818400019 yr = 598 184 000 s.
Kè864Traditional Chinese kè = 1/100 day = 864 s.
Hipparchic Cycle9586944000304 yr = 9 586 944 000 s.

* Month = 30 days; Year = 365 days. Adjust these values in JavaScript if you need calendar-specific accuracy.

Examples

  • Convert 2 hours to minutes:
    2 h → (2×3600 s) = 7200 s → (7200÷60) = 120 min
  • Convert 1 fortnight to days:
    1 fn → (1×1 209 600 s) = 1 209 600 s → (1 209 600÷86 400) = 14 d
  • Convert 5000 ms to seconds:
    5000 × 0.001 s = 5 s
  • Convert 3 centuries to years:
    3 c → (3×3 153 600 000 s) = 9 460 800 000 s → (9 460 800 000 ÷ 31 536 000) = 300 yr
  • Convert 10 Planck times to seconds:
    10 × 5.391247×10⁻⁴⁴ s = 5.391247×10⁻⁴³ s
  • Convert 1 Callippic cycle to years:
    1 × (2 396 736 000 s) = 2 396 736 000 s → (2 396 736 000 ÷ 31 536 000) ≈ 76 yr

Frequently Asked Questions

What is a “shake”?

In nuclear physics, a “shake” is defined as 10⁻⁸ seconds. It’s used to measure rapid processes in fission.

What is a “Svedberg”?

The Svedberg is 10⁻¹³ seconds, used in ultracentrifugation to describe sedimentation rates.

What is the “atomic unit of time”?

The atomic unit of time is defined as ħ/Eₕ ≈ 2.418884×10⁻¹⁷ seconds, where ħ is the reduced Planck constant and Eₕ is the Hartree energy.

Why are “month” and “year” approximate?

We define “month” as exactly 30 days and “year” as exactly 365 days. For calendar-accurate conversions (accounting for Feb/30/31 days, leap years), adjust those factors in the script.

Is this converter mobile-friendly?

Yes—once loaded, it runs fully client-side, and the layout reflows into a single column on narrow/mobile screens.

Can I use this converter offline?

After the page finishes loading, no further network requests are needed. You can convert time units entirely offline.