Time Unit Converter

Usage Instructions

About Time Unit Converter

Time Unit Converter is a fast and precise tool for converting between various time units. It supports common civilian units used in daily life, Chinese traditional time units for cultural reference, physics/astronomy professional units for scientific research, computer science units for technical calculations, and geological time units for educational purposes.

Key Features

Common Units: Millisecond, second, minute, hour, day, week, average calendar month, common year, leap year
Chinese Traditional Units: Chana (刹那), tanzhi (弹指), ke (刻), shichen (时辰), geng (更), xun (旬), ji (季), jinian (纪), dai (代), jiazi (甲子)
Physics/Astronomy Units: Picosecond, nanosecond, microsecond, femtosecond, attosecond, Planck time, leap second, Julian day/year, tropical year, sidereal year, eclipse year, Saros cycle
Computer Science Units: Tick, frame (60 fps / 30 fps), petasecond
Geological Units: Eon, era, period, epoch, age (reference only)
Real-time Conversion: Instant conversion as you type
High Precision: Accurate conversion factors with appropriate decimal precision
Privacy Protection: All conversions performed locally in your browser

Conversion Standards

Base Unit

All conversions use seconds (s) as the base unit. Seconds are the SI base unit for time, defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom. Every unit has a precise conversion factor to/from seconds, ensuring accuracy and consistency.

Precision Rules

Common Units: Display up to 4 decimal places, automatically removing trailing zeros
Advanced Units: Display up to 6 decimal places for high precision
Very Large/Small Values: Use scientific notation for values ≥ 1e12 or ≤ 1e-6, or < 1e-30
Approximate Units: Show the ≈ symbol to indicate approximate values
Automatic Formatting: Values automatically switch to scientific notation when appropriate

Special Unit Types

Approximate Units

Some units have approximate values due to their calculation methods:

Average Calendar Month: ≈ 30.4375 days (calculated as 365.25 days/year)
Chinese Traditional Units: Based on historical texts and folk conventions (e.g., chana ≈ 0.018s)
Astronomical Units: Based on long-term astronomical observations (e.g., tropical year ≈ 365.2422 days)
Planck Time: Quantum gravity constant ≈ 5.391247 × 10⁻⁴⁴ seconds

All approximate values show the ≈ symbol in the interface.

Range Units (Reference Only)

Geological time units (eon, era, period, epoch, age) are displayed for educational reference only. These units represent time ranges that vary by tens of millions to billions of years depending on the specific geological period, so precise conversion is not provided.

Unit Categories

Common Units

Millisecond (ms): 1 ms = 0.001 s
Second (s): SI base unit for time
Minute (min): 1 min = 60 s
Hour (h): 1 h = 3600 s
Day (d): 1 d = 86400 s
Week (wk): 1 wk = 604800 s
Average Calendar Month: ≈ 30.4375 days
Common Year: 365 days = 31536000 s
Leap Year: 366 days = 31622400 s

Chinese Traditional Time Units

These units are based on ancient Chinese timekeeping systems and Buddhist texts:

Chana (刹那): ≈ 0.018 s (from Buddhist scripture "Sanghi Vinaya")
Tanzhi (弹指): ≈ 7.2 s
Ke (刻): 15 minutes (ancient: 100 ke per day, modern: 96 ke per day)
Shichen (时辰): 2 hours (12 shichen per day, corresponding to the twelve earthly branches)
Geng (更): 2 hours (night timekeeping, 5 geng per night)
Xun (旬): 10 days (divided into upper/middle/lower xun per month)
Ji (季): 3 months (4 seasons per year)
Jinian (纪): 12 years
Dai (代): ≈ 25 years (folk convention: 25-30 years, using middle value)
Jiazi (甲子): 60 years (heavenly stems and earthly branches calendar cycle)

Physics/Astronomy Professional Units

High-precision units used in scientific research:

Picosecond (ps): 10⁻¹² s - Laser physics, ultrafast spectroscopy
Nanosecond (ns): 10⁻⁹ s - Semiconductor chips, optical communication
Microsecond (μs): 10⁻⁶ s - Precision instruments, pulse signals
Femtosecond (fs): 10⁻¹⁵ s - Femtosecond lasers, molecular dynamics
Attosecond (as): 10⁻¹⁸ s - Atomic inner-shell electron motion research
Planck Time (tₚ): ≈ 5.391247 × 10⁻⁴⁴ s - Quantum gravity theory (smallest measurable time unit)
Leap Second: 1 s - UTC correction for Earth's rotation errors
Julian Day (JD): 86400 s - Astronomical event date recording
Julian Year: ≈ 365.25 days - Astronomical standard year
Tropical Year: ≈ 365.2422 days - Earth's revolution period to vernal equinox
Sidereal Year: ≈ 365.2564 days - Earth's true revolution period around the sun
Eclipse Year: ≈ 346.6201 days - Moon's orbital node regression period
Saros Cycle: ≈ 6585.32 days (≈ 18 years 11 days 8 hours) - Eclipse repetition period

Computer Science Units

Units used in computing and digital systems:

Tick: ≈ 10-15 ms (Windows system kernel clock interrupt frequency)
Frame (60 fps): ≈ 16.67 ms - Video/game rendering at 60 frames per second
Frame (30 fps): ≈ 33.33 ms - Video rendering at 30 frames per second
Petasecond (Ps): 10¹⁵ s - Big data time span measurement

Geological Time Units (Reference Only)

These units represent geological time periods and are for educational reference:

Eon: Hundreds of millions to billions of years (e.g., Phanerozoic ≈ 541 million years)
Era: Tens of millions to hundreds of millions of years (e.g., Mesozoic ≈ 186 million years)
Period: Millions to tens of millions of years (e.g., Cretaceous ≈ 80 million years)
Epoch: Hundreds of thousands to millions of years
Age: Tens of thousands to hundreds of thousands of years

Use Cases

Daily Life: Convert between seconds, minutes, hours, days for scheduling and time management
Scientific Research: Convert between picoseconds, nanoseconds, and other physics units for experiments
Astronomical Calculations: Use Julian days, tropical years, and other astronomical units for observations
Computer Science: Calculate frame rates and system timing
Cultural Education: Learn about Chinese traditional time units and their historical significance
Geology Education: Reference geological time periods for educational purposes

Technical Notes

Year Type Selection

The tool provides a "Year Type" selector to choose between:

Common Year: 365 days (years not divisible by 4, or divisible by 100 but not by 400)
Leap Year: 366 days (years divisible by 4 and not by 100, or divisible by 400)

This allows accurate conversion calculations when working with calendar years.

Accuracy and Precision

All conversions use seconds as the intermediate base unit to avoid precision loss
Very small units (like Planck time) use high-precision floating-point arithmetic
Approximate values are clearly marked with the ≈ symbol
Scientific notation is automatically used for extremely large or small values

FAQ

Q: How do I reset all inputs?: A: Click the "Reset" button (rotating arrow icon) in the top-right corner of the input area to clear all input data and restore to the initial state.
Q: Which units are supported?: A: Supports common units (millisecond, second, minute, hour, day, week, month, year), Chinese traditional time units (chana, tanzhi, ke, shichen, geng, xun, ji, jinian, dai, jiazi), physics/astronomy professional units (picosecond, nanosecond, microsecond, femtosecond, attosecond, Planck time, Julian day/year, tropical year, sidereal year, eclipse year, Saros cycle), computer science units (tick, frame, petasecond), and geological time units (eon, era, period, epoch, age).
Q: What is the conversion precision?: A: All conversions use seconds as the base unit with precise conversion factors. Common units retain up to 4 decimal places, advanced units retain up to 6 decimal places, and very large or very small values use scientific notation. Approximate units show the ≈ symbol.
Q: Is data automatically saved? Will it be lost when refreshing the page?: A: Yes, input data is automatically saved to browser local storage. Refreshing the page won't cause data loss, and you can continue editing previously entered content. Data is automatically saved about 400ms after you stop typing.
Q: Can time values be negative?: A: No, time values do not allow negative input. If a negative number is entered, the system will handle it automatically.
Q: Why can't geological time units be converted?: A: Geological time units (eon, era, period, epoch, age) have extremely large time range differences. Different geological units with the same name may differ by tens of millions of years, so they are only displayed as knowledge references and do not provide precise conversion functionality.