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Date & Time

Date Difference Calculator

Calculate the difference between two dates in years, months, and days, plus total days, weeks, and optional business days. Toggle inclusive counting, include time, and add holidays as needed. Everything runs locally in your browser.

Difference Between Dates
Client-side onlyFast & private
Start date
End date
Options

Show totals in hours/min/sec

Count both start and end dates

Exclude weekends, optional holidays

Date only • Exclusive count
Notes

Calculations use your browser’s local timezone. Day counts use UTC-midnight diffs to avoid DST drift.

Results

Summary
  • Start: Wed, Jan 1, 2020 (Wednesday)
  • End: Thu, Sep 11, 2025 (Thursday)
  • Calendar difference: 5 years, 8 months, 10 days
Totals
  • Total days: 2,080
  • Weeks + days: 297 weeks + 1 days

How to Use the Date Difference Calculator

This free, client-side Date Difference Calculator measures the time between any two dates. Get an exact calendar difference in years, months, days, along with total days, weeks, and optional business day counts. Nothing is uploaded.

  1. Pick dates: Use the calendars to choose a Start and End date. Use Swap if needed.
  2. Include time (optional): Toggle on and set HH:MM for precise totals in hours/min/sec.
  3. Inclusive days: Turn on to count both the start and end dates in the total day count.
  4. Business days (optional): Excludes weekends; add holidays (YYYY-MM-DD, one per line) to omit them too.
  5. Read results: View calendar Y/M/D, total days, weeks + remainder, and business days. Copy or reset anytime.

Formulas

  • Calendar diff (Y/M/D): Borrow months/days across calendar boundaries.
  • Total days: ceil((End − Start)/86400000) using UTC-midnight diff; +1 if inclusive.
  • Weeks + days: weeks = ⌊days/7⌋, remainder days % 7.
  • Business days: Count weekdays, minus listed holidays.

Tips

  • Day counts use UTC-midnight differences to avoid daylight-saving shifts.
  • Holidays should be entered as ISO dates (e.g., 2025-12-25).
  • Calendar Y/M/D shows leftover days after full months are accounted for.