Time Converter
Enter a value and select units to convert
Enter a value and select units to convert
This time converter allows you to convert between various units of time, from the incredibly brief Planck time to millennia and beyond. Time measurement is fundamental across all human activities, from everyday scheduling to advanced scientific research. This tool handles common units like seconds, minutes, and hours, as well as specialized astronomical time units and ancient/historical time periods.
Time Measurement Systems
Standard Time Units
The standard units of time measurement used in everyday life:
- Second [s]: The base unit of time in the International System of Units (SI)
- Minute [min]: 60 seconds
- Hour [h]: 60 minutes or 3,600 seconds
- Day [d]: 24 hours or 86,400 seconds
- Week [wk]: 7 days or 604,800 seconds
- Month [mo]: Approximately 30 days (varies by month)
- Year [yr]: 365 days (or 366 in leap years)
Extended Time Periods
Units for measuring longer time spans:
- Decade [dec]: 10 years
- Century [cent]: 100 years
- Millennium [mill]: 1,000 years
- Quinquennial: 5 years
- Septennial: 7 years
- Octennial: 8 years
- Novennial: 9 years
- Quindecennial: 15 years
Scientific/Small Time Units
Extremely small units of time used in scientific contexts:
- Planck time [tp]: The smallest theoretically measurable unit of time (5.4 × 10^-44 seconds)
- Attosecond [as]: 10^-18 seconds
- Femtosecond [fs]: 10^-15 seconds
- Picosecond [ps]: 10^-12 seconds
- Nanosecond [ns]: 10^-9 seconds
- Microsecond [μs]: 10^-6 seconds
- Millisecond [ms]: 10^-3 seconds
- Shake [shake]: 10^-8 seconds (used in nuclear physics)
Astronomical Time Units
Time units based on astronomical observations and phenomena:
- Sidereal second [sid s]: Based on Earth's rotation relative to distant stars
- Sidereal minute [sid min]: 60 sidereal seconds
- Sidereal hour [sid h]: 60 sidereal minutes
- Sidereal day [sid d]: 23 hours, 56 minutes, 4.1 seconds (approx.)
- Sidereal year [sid yr]: 365.256363 days
- Tropical year [trop yr]: 365.242190 days
- Anomalistic year [anom yr]: 365.259636 days
Other Time Units
Specialized or historical time units:
- Fortnight [fn]: 14 days or 2 weeks
- Quarter [qtr]: 3 months
- Leap year [leap y]: 366 days
Common Time Conversions
| From | To | Multiply By |
|---|---|---|
| Seconds | Minutes | 0.01667 (divide by 60) |
| Minutes | Seconds | 60 |
| Minutes | Hours | 0.01667 (divide by 60) |
| Hours | Minutes | 60 |
| Hours | Days | 0.04167 (divide by 24) |
| Days | Hours | 24 |
| Days | Weeks | 0.14286 (divide by 7) |
| Weeks | Days | 7 |
| Months (average) | Days | 30.44 (365.25/12) |
| Years | Days | 365.25 (includes leap years) |
| Years | Months | 12 |
| Milliseconds | Seconds | 0.001 |
| Seconds | Milliseconds | 1,000 |