Is my data sent to a server?

No. All calculations are performed entirely within your browser.

What if the end date is before the start date?

The tool will return the absolute difference in days (negative numbers are not shown).

Why are months and years approximate?

Because month lengths vary (28–31 days), exact counts depend on the specific months. This tool uses 30.44 days per month as an approximation.

Can I calculate business days (excluding weekends)?

This tool calculates total calendar days. For business days excluding weekends and holidays, please use our Business Day Calculator.

📅

date diff calculator,

Date Difference Calculator

Instantly calculate the difference between two dates in days, weeks, and months.
Also supports adding or subtracting days from a date.

📊

Diff Calculation

Days, weeks, months, years at once

➕

Date Addition

Add or subtract days from any date

📆

Today-based

Elapsed / remaining days from today

Start Date

End Date

🔒All calculations are performed locally in your browser.

about,

About

A free online calculator that instantly computes the difference between two dates in days, weeks, months, and years. Perfect for project planning, anniversaries, and deadline management.

The date addition mode answers "What date is 30 days from today?" All processing is browser-based with no server loads.

how to use,

How to Use

STEP 1

Select Mode

Choose date difference or add/subtract days mode.

STEP 2

Enter Dates

Use the date pickers to input your dates.

STEP 3

View Results

Results update in real time as you change the dates.

glossary,

Glossary

Day Difference: The number of calendar days between two dates, calculated precisely.
Leap Year: A year with 366 days (Feb 29 exists). Divisible by 4, except century years unless divisible by 400.
Gregorian Calendar: The internationally used solar calendar. JavaScript date arithmetic is based on it.
UTC: Coordinated Universal Time — the international time standard.

faq,

FAQ

Q.Is my data sent to a server?: No. All calculations are performed entirely within your browser.
Q.What if the end date is before the start date?: The tool will return the absolute difference in days (negative numbers are not shown).
Q.Why are months and years approximate?: Because month lengths vary (28–31 days), exact counts depend on the specific months. This tool uses 30.44 days per month as an approximation.
Q.Can I calculate business days (excluding weekends)?: This tool calculates total calendar days. For business days excluding weekends and holidays, please use our Business Day Calculator.