Calculate exact age or the duration between two dates — down to the second.
Someone born on 1990-06-15 wants to know their exact age today.
Date arithmetic follows the proleptic Gregorian calendar and ignores historical calendar reforms; leap years and DST transitions can shift wall-clock results.
To calculate days between dates: enter start and end dates — the tool returns total days, business days, weekend count, and the precise years-months-days breakdown, handling leap years automatically.
FreeToolHub Date Difference Calculator is a free browser-based tool that computes days, weekdays, and full year-month-day spans between two dates, no signup.
Calculate exact difference between two dates in years, months, days, hours. Also calculates age from birthday. Free, no signup.
This calculator measures the exact span between two dates in every unit the real world asks for: total days, business days excluding weekends, weekend day counts, and the calendar-precise breakdown in years, months, and days. It doubles as an age calculator — enter a birthdate and today's date for exact age per legal convention — and handles boundaries that trip manual math: inclusive or exclusive end dates, leap years, and month-end asymmetries like January 31 to February 28. All computation is instant and local.
Project managers compute deadlines, notice periods, and working-day timelines without counting calendar squares. HR and payroll teams verify tenure, benefit eligibility, and probation spans precisely. Contracts teams measure cure periods, lease terms, and statute windows in exact days. Event planners count down days to launch and reconcile vendor lead times. Legal-adjacent work especially benefits: deadlines computed inclusive-versus-exclusive change outcomes, and this tool states which convention it applied.
(1) Enter the start and end dates — any order; the tool takes the absolute span. (2) Choose whether to include the end date, which adds one day for deadline and notice-period conventions. (3) Read the results: total days, business days, weekend days, and the years-months-days breakdown computed calendar-precisely. (4) For age, enter the birthdate as start and today as end; the years-months-days form matches legal age. Leap days count automatically because the arithmetic runs on real calendar dates, not fixed 365-day years.
The inclusive-versus-exclusive question decides real disputes, and the answer depends on the governing rule. Contract law defaults in most US jurisdictions: the day of the triggering event is excluded, and if the deadline falls on a weekend or holiday, it rolls to the next business day unless the contract says otherwise. Court rules under FRCP 6(a) spell this out explicitly for federal filings — exclude the trigger day, include the last day, extend weekends and holidays — and many state rules mirror it. Notice periods for leases and employment typically follow the same exclude-start, include-end reading. Where ambiguity is expensive, the professional habit is to state the convention in the document itself: within 30 days, computed excluding the date of this notice. This calculator's include-end-date toggle exists so you can compute under whichever convention your rule applies, and see the one-day difference explicitly rather than discovering it in a dispute.
Enter the start and end dates — the calculator counts total days, weekdays, and weekend days, plus the breakdown in years, months, and days, handling leap years automatically.
By default this tool computes the exclusive span (end minus start). Toggle include end day to add one day, which matters for deadlines, notice periods, and interest day-count conventions.
Use the weekday count, which excludes Saturdays and Sundays across the full span. For holidays, subtract them manually or check whether your contract specifies calendar or business days.
The tool counts complete years, then remaining months, then days — matching legal age convention where someone born March 15, 1990 turns 36 on March 15, 2026, not before.
It calculates full years, months, and days between your birthday and today, accounting for leap years and varying month lengths. For example, if born on March 15, 1990, and today is August 15, 2026, the result is 36 years, 5 months, 0 days. It also shows total days and total weeks lived.
The companion countdown tool calculates business days (Monday through Friday, excluding weekends). For holidays, check the countdown tool which also supports workday calculation. The date difference tool focuses on calendar days, showing the breakdown in years, months, weeks, days, hours, and minutes.
This tool is also known by these tasks — each link opens the same tool with a focused guide:
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