Date Calculator

How to Use Date Calculator

1
Choose a calculation mode
Select Date Difference (how many days between two dates) or Date Addition (add/subtract days from a date).
2
Enter the dates
Use the date pickers to enter the start and end dates, or a base date and number of days to add.
3
Click Calculate
The result shows the exact number of days, weeks, months, and years between dates, or the resulting date.
4
Use the countdown option
See how many days remain until a future date, or how many days have passed since a past date.

Calculate how many working days remain until a project deadline to set realistic milestones.

Find exact age in years, months, and days from a birth date.

Calculate the expiration date of a contract, subscription, or license given a start date and duration.

Count down the exact number of days until a wedding, vacation, product launch, or other important date.

Add 30, 60, or 90 days to an invoice date to calculate the exact payment due date.

Month differences are calculated as calendar months. Fractional months are expressed in days.

Yes. February 29 in leap years is correctly accounted for in all calculations.

Currently the tool counts all calendar days. Working-day calculations (excluding weekends) may be added in a future update.

No. All date calculations happen in your browser.

Use the date pickers for correct input. Dates are displayed in your locale's format.