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Date Difference Calculator

Pick two dates to see the exact difference in years, months, weeks, and days.

About This Tool

Free date difference calculator online — find the exact number of days, weeks, months, and years between any two dates. Enter a start date and an end date and instantly see the full breakdown: total days, total weeks, and a years/months/days split. This tool is useful for calculating contract durations, project timelines, time since a milestone or event, countdowns to deadlines, and legal or financial date-range calculations like interest accrual periods or notice periods. Everything runs locally in your browser using native JavaScript date logic — no data is sent anywhere, and the result updates instantly as you change either date. Works correctly across leap years and varying month lengths.

How to Use

  1. 1

    Pick the start date

    Select the earlier date using the date picker.

  2. 2

    Pick the end date

    Select the later date — defaults to today.

  3. 3

    Read the difference

    See total days, weeks, and a years/months/days breakdown update instantly.

Frequently Asked Questions

How many days are between two dates?+
Enter both dates and the tool subtracts them, correctly accounting for leap years, to give you the exact total number of days along with a years/months/days breakdown.
Does it count the start or end date?+
The calculator counts the number of full days elapsed between the two calendar dates (exclusive of one endpoint), which matches how "days between" is conventionally calculated.
Can I calculate a date range in the past?+
Yes — both the start and end date can be any date, past or future, so you can measure durations entirely in the past or spanning into the future.

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