calculator
Date Difference Calculator 📅

Calculate the exact number of days, weeks, months, and years between any two dates. Includes workday count and exact breakdown.

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days apart
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Weeks
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Months
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Years
📋 Working Days (Mon–Fri)
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📋 How To Use
1
Enter the start date. Click the first date field and select or type your starting date. This can be any past, present, or future date.
2
Enter the end date. Select the second date you want to measure to. The end date can be before the start date — the calculator handles both directions.
3
Choose your options. Toggle whether to include the end date in the count (useful for event durations) and whether to show the working day count alongside the total.
4
Click Calculate. See the total days, weeks, months, years, an exact breakdown like “2 years, 3 months, 14 days,” and the number of working days between the two dates.
⚙️ How It Works
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Total Days
The difference in milliseconds between the two dates is converted to days. Leap years are handled automatically since the calculation uses actual calendar timestamps.
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Exact Breakdown
The exact breakdown (years, months, days) accounts for varying month lengths. February, for example, has 28 or 29 days — all of this is accounted for precisely.
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Working Days
Working days are counted by iterating through each day in the range and excluding Saturdays and Sundays. Public holidays are not excluded as these vary by country.
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Any Direction
The calculator automatically detects if the end date is before the start date and handles the result correctly, always showing a positive number of days regardless of order.
❓ Frequently Asked Questions
Calendar days count every day including weekends and holidays. Working days (also called business days) only count Monday through Friday, excluding weekends. This is useful for project planning, legal deadlines, and calculating notice periods where only business days count.
Whether to include the end date depends on the context. For event duration (e.g. a 3-day conference from Monday to Wednesday), including the end date gives you 3 days. Without including it, you get 2 days. For calculating time elapsed between two dates (e.g. how many days until an appointment), you typically do not include the end date.
Yes. The calculator uses JavaScript’s native Date object which automatically handles leap years. When counting days across a leap year, the extra day in February is included in the total. This applies to both the total day count and the exact years/months/days breakdown.
Yes. You can use any combination of past, present, and future dates. This makes the tool useful for countdown timers, project deadlines, contract end dates, anniversaries, and any planning that requires knowing the distance between two specific calendar dates.
No. The working days count excludes only weekends (Saturday and Sunday). Public holidays are not removed because they vary widely by country, region, and employer. For precise business day calculations that exclude specific holidays, you would need to manually subtract the relevant public holidays from the result.
The exact breakdown (e.g. “1 year, 4 months, 12 days”) is calculated by first finding the full years, then the remaining full months accounting for variable month lengths, then the remaining days. This mirrors how people naturally count time and is the same method used in legal and administrative contexts.
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