Conversion
result = value × s(source) / s(target)
Duration Converter
Convert a duration between milliseconds, seconds, minutes, hours, days, weeks and working days of adjustable length, using fixed, checkable ratios.
Used only when converting to or from working days.
Enter a valid duration greater than or equal to zero.
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How does this tool work?
How many minutes are in a week, how many days is a million seconds, how many 7.5-hour days make 37.5 hours? This converter moves between duration units, from milliseconds to weeks, using fixed ratios. It also adds a unit that most converters forget: the working day, whose length you choose. The result shows up to twelve significant digits, and the swap button starts from the result to convert the other way.
The value is first expressed in seconds, then divided by the number of seconds in the target unit. The ratios are those of the units accepted for use with the International System: 1 min = 60 s, 1 h = 3,600 s, 1 d = 86,400 s, plus 1 week = 7 d and 1 ms = 0.001 s.
A working day is worth the number of hours you enter (7 h by default). It only matters when one of the two units is “working days”; 1 day always stays 24 hours.
Months and years are left out on purpose: a month has 28 to 31 days and a year 365 or 366. For those, start from real dates.
The 86,400-second day is a conventional duration. A civil day can last 23 or 25 hours when clocks change, and leap seconds have occasionally been added to UTC; those cases belong to calendars, not to unit conversion.
How to use this tool
Enter the value
Any number greater than or equal to zero; decimals are accepted.
Choose both units
The source unit on the left, the target unit on the right.
Set the working day if needed
The field appears as soon as “working days” is selected.
Swap or share
The swap button exchanges the units starting from the result; the calculation link keeps the value, units and day length.
Conversion formula
Every conversion goes through the second, the SI base unit of time.
Working day
s(working day) = L × 3600
L is the chosen working-day length in hours.
- v
- value entered
- s
- seconds in one unit (ms: 0.001; min: 60; h: 3,600; d: 86,400; wk: 604,800)
- L
- working-day length in hours
Use cases
Technical settings
Convert a timeout, cache lifetime or latency between milliseconds, seconds and minutes.
Workload estimates
Turn a number of hours into 7, 7.5 or 8-hour working days for a quote or a plan.
Orders of magnitude
Make a count of seconds or minutes meaningful by expressing it in days or weeks.
Checking a spreadsheet
Confirm a factor of 60, 1,440 or 86,400 before using it in a formula.
Examples
One million seconds
1,000,000 ÷ 86,400 ≈ 11.57 days, i.e. 11 days 13 h 46 min 40 s.
Input
1,000,000 s → daysResult
11.5740740741 dA week in minutes
7 × 24 × 60 = 10,080.
Input
1 wk → minutesResult
10,080 minA 37.5-hour week
37.5 × 3,600 ÷ (7.5 × 3,600) = 5.
Input
37.5 h → working days (7.5 h)Result
5 daysA 90-minute video
90 ÷ 60 = 1.5, that is 1 h 30 (not 1.30 h).
Input
90 min → hoursResult
1.5 hTips and best practices
- A decimal number of hours is not hours-and-minutes notation: 2.75 h is 2 h 45. The decimal hours converter does that translation.
- For a 7 h 48 day (39 h over 5 days), enter 7.8, not 7.48.
- Remember the key factors: 1,440 minutes and 86,400 seconds per day, 10,080 minutes and 604,800 seconds per week.
- For the time between two dates, with months and leap years, use the date difference calculator.
- Negative values are not accepted: a duration is a gap, always zero or positive.
Sources and references
- BIPM — SI Brochure: units of time (opens in a new tab)Page in English
Frequently asked questions
How many seconds are in a day?
86,400: 24 hours × 60 minutes × 60 seconds. A week has 604,800.
Why can’t I convert to months or years?
Because their length varies: 28 to 31 days for a month, 365 or 366 for a year. A fixed factor would be wrong for some periods, so it is better to calculate from dates.
How do I convert hours to working days?
Divide by the length of a day. With 7-hour days, 35 h is 5 days; with 8-hour days, 35 h is 4.375 days. Set that length in the dedicated field.
Is a day always 24 hours?
As a unit of duration, yes: 1 d = 86,400 s. On a local calendar, the day clocks change lasts 23 or 25 hours, which only a calculation between real dates and times can reflect.
How many hours is 1,000 minutes?
1,000 ÷ 60 ≈ 16.67 h, which is 16 h 40 min.
How precise is the result?
Twelve significant digits, enough for every everyday conversion. Fractions such as 1/3 are still rounded: 20 minutes gives 0.333333333333 h.
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