Date Difference Calculator

By the FastFreeTools Editorial Team · Last reviewed: May 2026 · See our Editorial Policy for methodology, sourcing, and disclaimers.

Calculate the exact difference between two dates in years, months, days, weeks, business days, and hours.

About this tool

Calculating the exact time between two dates is surprisingly complex — months have different lengths, leap years add days, and business day calculations exclude weekends. Our Date Difference Calculator handles all of this, showing the difference in years, months, days, weeks, total days, business days, hours, and minutes. It's invaluable for project planning, calculating contract durations, determining age differences, counting down to events, and computing interest periods. The calculator correctly handles all edge cases including leap years and month-end dates.

How to use Date Difference Calculator

Select or enter the start date.
Select or enter the end date.
View the difference in multiple units: years, months, days, weeks.
Check the business days count (excluding weekends).

Tips & best practices

Business days exclude Saturdays and Sundays.
The calculator handles leap years automatically.
Swap the dates to calculate in either direction.
Use this for project planning and deadline calculations.

Common use cases

Calculating project timelines and deadlines.
Determining contract durations and rental periods.
Planning events and counting down to important dates.
Computing interest periods for financial calculations.

Privacy

This tool runs entirely in your browser. We do not upload, store, log, or process your input on any server. Open your browser's DevTools Network tab to verify — there is no outbound request with your data. See our Privacy Policy for details.

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