📅 Calendar Mathematics & Duration
Date Difference Calculator
Calculate the exact duration, calendar days, weeks, months, and business working days between two dates.
Quick Presets:
+30 Days
+90 Days (Quarter)
+180 Days (Half Year)
+1 Year (365 Days)
Days Remaining in Year
Duration Difference
Calculating...
Time Breakdown Metrics:
Calendar Days
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Business Days
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Weekend Days
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Total Weeks
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Total Hours
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% of Full Year
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Calendar Systems, Project Deadlines, and Business Day Counting
Measuring time between two dates is essential in legal contracts, financial interest accrual (such as 30/360 or Actual/Actual day-count conventions), project management sprints, and flight itineraries.
Business Days vs. Calendar Days
In supply chain logistics, contract fulfillment, and banking settlement (such as T+2 trade clearing), elapsed time is measured strictly in business days (working days). Standard calendar days include Saturdays and Sundays, while business days count only weekdays.
Frequently Asked Questions
This calculator excludes all Saturdays and Sundays from the business day total. Because statutory public holidays vary widely by country, state, and municipality, local legal holidays should be subtracted according to your regional statutory calendar.
Standard mathematical and calendar convention treats duration as $Date_2 - Date_1$ (e.g. from Monday to Tuesday is 1 day). If you need an inclusive count (both start and end dates included), simply add 1 to the calendar day total.