Date & TimeFormula-based · Runs in your browser

Date Difference Calculator

Find the exact calendar difference and total days between two dates.

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Inputs

Enter the values you know. Optional fields may be left empty.

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Result

Updates as valid inputs change.

Calculated locally
Exact difference
Total days
Weeks and days
Average months

Saved locally, explained clearly

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Calculation steps

Follow what happened from the selected formula to the displayed answer.

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  1. 1

    Formula selected

    The calculator uses the following formula or method.

    Exact difference uses calendar years, months, and remaining days

  2. 2

    Values entered

    Your values are placed into the calculation.

    Enter values to see what is used in this step.

  3. 3

    Result calculated

    The formula or method produces the following result values.

    Results will appear after a successful calculation.

  4. 4

    Answer formatted

    Displayed values are rounded and formatted using each output’s configured precision.

Scenario comparison

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Recent calculations

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Data and privacy

How it works

The exact result follows calendar month lengths and leap years. Total days uses UTC date boundaries.

Input query strings and outputs

Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.

Input query strings

2
  • ?startDate= Start date

    Date · Required · Default: 2026-01-01

  • ?endDate= End date

    Date · Required · Default: 2026-08-18

Outputs

4
  • exactDifference Exact difference

    Text · Primary output

  • totalDays Total days

    Whole number

  • weeksAndDays Weeks and days

    Text

  • averageMonths Average months

    Number

Sources
  • No external reference is listed for this calculator. Its formula and variable definitions are shown above.
Limitations
  • Calendar results depend on the selected dates and time-zone assumptions. Local holidays and daylight-saving changes are included only where stated.