Convert time units — seconds, minutes, hours, days, weeks, months, years.
| Unit | Name | Value |
|---|---|---|
| ms | Millisecond | 31536000000 |
| s | Second | 31536000 |
| min | Minute | 525600 |
| hr | Hour | 8760 |
| d | Day | 365 |
| wk | Week | 52.142857 |
| mo | Month (30d) | 12.166667 |
Formula: Month = Year × 12
Multiply any year value by 12 to get month.
Reverse: Year = Month × 0.08333
Common year values — factor: 1 yr = 12 mo
| Year (yr) | Month (mo) | Context |
|---|---|---|
| 1 yr | 12 mo | One year |
| 2 yr | 24 mo | Two years |
| 5 yr | 60 mo | 5 years |
| 10 yr | 120 mo | One decade |
| 25 yr | 300 mo | Quarter century |
| 50 yr | 600 mo | Half century |
| 100 yr | 1,200 mo | One century |
| 200 yr | 2,400 mo | Two centuries |
| 500 yr | 6,000 mo | Half millennium |
| 1,000 yr | 1.2e+04 mo | One millennium |
| 2,000 yr | 2.4e+04 mo | 2 millennia |
| 5,000 yr | 6e+04 mo | Ancient Egypt |
| 1e+04 yr | 1.2e+05 mo | End of last ice age |
| 1e+05 yr | 1,200,000 mo | H. sapiens timeline |
| 1,000,000 yr | 12,000,000 mo | Early humans |
Years × 12 = months. Exact by calendar definition.
1 yr = 12 mo, 5 yr = 60 mo, 10 yr = 120 mo.
Months ÷ 12 = years.
Models multi-year revenue forecasts, DCF valuations, and amortization schedules.
Designs infrastructure with 20-50 year horizons for roads, utilities, and buildings.
Calculates life expectancy, annuity durations, and policy terms in years.
Measures stellar distances in light-years and planetary orbital periods in years.
Analyzes temperature records and climate projections spanning decades and centuries.
Tracks employee tenure, pension vesting schedules, and anniversary milestones in years.
The year (approximately 365.25 days) is defined by Earth's orbital period around the Sun. Julius Caesar introduced the Julian calendar (365.25 days) in 45 BCE; Pope Gregory XIII refined it to the Gregorian calendar in 1582 to correct accumulated drift.
Years organize human civilization: fiscal years, academic years, election cycles, and long-term planning. The Julian year (exactly 365.25 days = 31,557,600 seconds) is used as a standard in astronomy and this converter.
Interesting fact: A year on Venus is shorter than its day — Venus takes 225 Earth days to orbit the Sun but 243 Earth days to rotate once. A year on Neptune lasts 164.8 Earth years.
The month originated with the lunar cycle (~29.5 days), used by ancient Mesopotamian, Egyptian, and Chinese calendars. The Gregorian calendar months (28–31 days) are a solar compromise that drifts from the lunar cycle.
Months define billing cycles, salary periods, pregnancy tracking, and seasonal planning. The average Gregorian month is 30.437 days; this conversion uses 30.44 days (2,629,800 seconds) as the standard average.
Interesting fact: The word 'month' derives from 'moon' in Germanic languages. Islam and the Hebrew calendar still use lunar months, which is why Ramadan and Passover shift relative to the Gregorian calendar each year.
Converting year to month is a common task across science, engineering, and everyday planning. The time scale spans from nanoseconds in computing to centuries in history, and having accurate conversions helps when comparing measurements across different systems or disciplines.
As a quick reference: 5 yr = 60 mo and 10 yr = 120 mo. For the reverse: 1 mo = 0.08333 yr. The exact conversion factor is 1 yr = 12 mo.
All conversions are performed in IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.