Date Calculator

Add or subtract days from a date, or calculate the difference between two dates in years, months, weeks, and days.

Calculator

Results

Enter values and click Calculate

Results will appear here

Adding Days to a Date and Finding Date Differences

Use the add-days mode to add days to a date β€” for example, a 90 day calculator to find the date 90 days from today, a deadline, or a due date. Subtracting days works the same way in reverse. Both modes handle calendar months and leap years correctly, so adding 30 days in February and adding 30 days in January produce different results.

The difference mode acts as a days calculator from date to date: pick two dates and it reports the gap in years, months, weeks, and days. Common uses include counting the days until a vacation, working out how many days remain on a contract, and planning milestones and anniversaries.

Whether you need a date calculator in days, a month calculator for date math, or a general calendar calculator for planning, this time and date calculator covers it in one tool.

How to Use

The calculator correctly accounts for leap years (years divisible by 4, except century years not divisible by 400) when adding/subtracting days or calculating differences.

How It Works

Add or subtract days from a date, or calculate the difference between two dates in years, months, weeks, and days.

Formula / Calculation Method

This calculator uses standard mathematical formulas for accurate results.

Example

Try the calculator above with your own values to see personalized results.

Frequently Asked Questions

How does the calculator handle leap years?

The calculator correctly accounts for leap years (years divisible by 4, except century years not divisible by 400) when adding/subtracting days or calculating differences.

Can I calculate business days only?

This calculator counts calendar days. For business days, you would need a specialized business day calculator.