Time Converter
Convert durations between nanoseconds, seconds, minutes, hours, days, weeks, months, years and centuries, with a plain-language breakdown and clock format.
1 day = 24 h = 1,440 min = 86,400 s
Exact Units vs Average Units
Seconds through fortnights have fixed lengths. Months, quarters and years don't, so the converter uses the Gregorian calendar average: 365.2425 days per year, the average over its 400-year leap-year cycle.
| Unit | Seconds | Exact? |
|---|---|---|
| Nanoseconds | 1 × 10⁻⁹ | Yes |
| Microseconds | 1 × 10⁻⁶ | Yes |
| Milliseconds | 0.001 | Yes |
| Seconds | 1 | Yes |
| Minutes | 60 | Yes |
| Hours | 3,600 | Yes |
| Days | 86,400 | Yes |
| Weeks | 604,800 | Yes |
| Fortnights | 1,209,600 | Yes |
| Months (average) | 2,629,746 | Average |
| Quarters (average) | 7,889,238 | Average |
| Years (average) | 31,556,952 | Average |
| Decades | 315,569,520 | Average |
| Centuries | 3.1556952 × 10⁹ | Average |
How Long Is a Month?
Calendar months run from 28 to 31 days, so "one month" can mean anything from 672 to 744 hours. The average month is a twelfth of an average year: 30.44 days. Use it to compare rates, but count the actual days for billing periods, notice periods and deadlines.
| Month | Days | Hours | Minutes |
|---|---|---|---|
| February (common year) | 28 | 672 | 40,320 |
| February (leap year) | 29 | 696 | 41,760 |
| April, June, September, November | 30 | 720 | 43,200 |
| Average month (this converter) | 30.4369 | 730.485 | 43,829.1 |
| January, March, May, July, August, October, December | 31 | 744 | 44,640 |
Worked Example: A 90-Day Free Trial
A software trial lasts 90 days. Is that "three months"?
Step 1: Days to weeks (exact)
Step 2: Days to average months
Almost, but not quite. Three calendar months is 89 to 92 days depending on which months they are. A 90-day trial starting 1 February (in a common year) runs until 1 May, a day past three months, while one starting 1 July ends on 28 September, two days short. If an exact end date matters, count the days on a calendar rather than converting.
Working Time Conversions
Payroll and project estimates use working time, not calendar time. A "day" of work is usually 8 hours, not 24, so convert through hours rather than through the day unit.
| Period | Hours | Minutes |
|---|---|---|
| Working day | 8 | 480 |
| Working week (5 × 8 h) | 40 | 2,400 |
| Working year (52 × 40 h) | 2,080 | 124,800 |
The 2,080-hour working year is the usual basis for converting an hourly rate to an annual salary: $30 an hour × 2,080 = $62,400 a year, before paid leave and holidays.
Milliseconds, Microseconds and Nanoseconds
Below a second, each named unit is a thousand times smaller than the last. A 250 ms page delay is 0.25 s, 250,000 µs or 250,000,000 ns. Software timings mix these freely, so a misread unit is off by a factor of a thousand.
Everyday Durations in Every Unit
| Duration | Seconds | Hours | Days | Breakdown |
|---|---|---|---|---|
| Blink of an eye | 0.3 | 8.333 × 10⁻⁵ | 3.472 × 10⁻⁶ | 300 milliseconds |
| Feature film | 7,200 | 2 | 0.083333 | 2 hours |
| Marathon world-class finish | 7,260 | 2.016667 | 0.084028 | 2 hours, 1 minute |
| Full night's sleep | 28,800 | 8 | 0.333333 | 8 hours |
| One million seconds | 1,000,000 | 277.777778 | 11.574074 | 1 week, 4 days |
| One billion seconds | 1 × 10⁹ | 277,777.777778 | 11,574.074074 | 31 years, 8 months |
Frequently asked questions
How many seconds are in a year?
31,556,952 for an average Gregorian year (365.2425 days), 31,536,000 for a 365-day year and 31,622,400 for a leap year.
How do I enter 1 hour 30 minutes?
As a decimal in hours, 1.5, or as 90 minutes. The result line also shows durations in clock format, so 5,400 seconds displays as 1:30:00.
Does a day always have 24 hours?
In this converter, yes. On a real clock, days with a daylight-saving change have 23 or 25 hours, so use actual timestamps for those.
What is a fortnight?
Two weeks: 14 days or 336 hours. It's common in British and Australian English, especially for pay periods.
Related Tools
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Switch between Unix timestamps and readable dates.
Convert years to decades.
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