Time Converter
Convert seconds, minutes, hours, days, weeks, months and years.
About time units
Time units up to the week are exact: a day is 86,400 seconds by definition. Months and years are not. Calendar months run from 28 to 31 days and years are 365 or 366, so this converter uses the mean Gregorian year of 365.2425 days and a month of one twelfth of that. For a specific date range, count the actual days.
A day here is a duration of 86,400 seconds. Unless explicitly labeled Julian, months and years use the mean Gregorian convention (365.2425 days per year; one twelfth per month), rather than the actual length of a particular calendar interval.
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The conversions people look up most in this category.
All units
Compare unit values in the base unit. Numbers are rounded to 8 significant digits; conventions and assumptions appear beside the units.
| Unit | Symbol | 1 unit in s |
|---|---|---|
| nanosecond | ns | 1e-9 |
| microsecond | µs | 0.000001 |
| millisecond | ms | 0.001 |
| second | s | 1 |
| minute | min | 60 |
| hour | h | 3,600 |
| dayThe calendar day is exactly 86,400 s here. Actual solar days vary by milliseconds, and leap seconds have occasionally been added to civil time. | d | 86,400 |
| week | wk | 604,800 |
| fortnight | fn | 1,209,600 |
| monthA month is not a fixed quantity: calendar months run from 28 to 31 days. This converter uses one twelfth of the mean Gregorian year (30.436875 days). For a specific calendar month, count the actual days. | mo | 2,629,746 |
| yearA calendar year is 365 days, or 366 in a leap year. This converter uses the mean Gregorian year of 365.2425 days, which is the long-run average once leap years are included. | yr | 31,556,952 |
| Julian year | a | 31,557,600 |
| decade | dec | 315,569,520 |
| century | c | 3,155,695,200 |
| millennium | ky | 31,556,952,000 |
All conversion pages
Each page has the formula, worked examples and a reference table.