Date Difference & Calendar Calculator
Calculate date spans, working days, and future milestone deadlines accurately.
Total Days Difference
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Years, Months, Days
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Weeks & Days
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Business Days
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Total Hours
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How to Use Date Calculator
- Choose 'Difference Between Dates' or 'Add / Subtract Days' mode.
- Pick your start date and end date from the calendar selectors.
- Check 'Include end date' if counting inclusive calendar intervals.
- Inspect total days, weeks, business days (skipping weekends), and full year/month breakdown.
Technical Specifications & How It Works
The date difference engine evaluates elapsed time down to individual milliseconds while correctly handling varying month lengths and leap years.
Business day counting skips Saturdays and Sundays, computing true project work days.
Calculations run entirely client-side using JavaScript Date and Intl APIs.
Frequently Asked Questions
How does the date calculator handle leap years?
JavaScript native Date objects automatically account for leap year February 29th occurrences across all calendar years.
Are public holidays excluded from business days?
This tool skips standard Saturday and Sunday weekends; regional bank holidays vary by jurisdiction and can be adjusted manually.
Can I calculate negative dates backwards?
Yes, subtracting days or selecting an earlier end date accurately calculates historical date offsets.
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