Date Calculator
Calculate date differences or add and subtract days from any date.
How the Date Calculator Works
The Date Calculator helps you find the exact difference between two dates or compute a new date by adding or subtracting days. It calculates complete years, months, and remaining days, as well as total days, weeks, and business days (excluding weekends).
In Add/Subtract mode, simply choose a starting date and specify how many days to add or subtract. The calculator handles month boundaries, leap years, and varying month lengths automatically. To calculate someone's exact age, try our age calculator. For time arithmetic (adding hours, minutes, seconds), use the time calculator.
Frequently Asked Questions
How are business days calculated?
Business days are calculated by counting all days between two dates, excluding Saturdays and Sundays. Public holidays are not excluded as they vary by country and region.
Does the calculator handle leap years?
Yes. The calculator uses actual calendar dates, so leap years (including February 29) are automatically handled in all calculations.
Can I calculate backwards from a date?
Yes. Use the Add/Subtract Days tab and select Subtract Days to find a date in the past. For example, you can find what date was 90 days before today.
What is the difference between total days and business days?
Total days counts every calendar day between two dates. Business days (also called working days) excludes weekends (Saturday and Sunday), giving you the number of weekdays between the dates.