What is Date Calculator?

The Date Calculator is a free online tool that calculates the exact difference between two dates or performs date arithmetic by adding or subtracting a period from a specific date. It can easily handle date calculations frequently needed in daily life and work, such as project duration calculation, work days calculation, D-Day counting, and contract period verification. It calculates accurate differences in years, months, and days, automatically accounting for leap years and varying days in each month. You can get accurate results with just a few clicks without complex manual calculations.

How to Use

1. Select 'Date Difference' or 'Date Arithmetic' from the top tab for the desired function.
2. Date Difference mode: Select start and end dates, and the difference between the two dates is automatically calculated.
3. Date Arithmetic mode: Select a reference date and enter the period (years/months/days) to add or subtract.
4. Results are displayed immediately and can be checked in detail in years, months, and days.

Use Cases

• •Calculate work period between project start and deadline dates
• •Calculate exact number of work days from employment start date to present
• •Calculate D-Day to important dates (anniversary, birthday, etc.)
• •Verify contract period between start and end dates in contracts
• •Calculate visa expiration date 90 days from travel departure date
• •Calculate expected delivery date (pregnancy confirmation date + 280 days)
• •Calculate loan maturity date (loan date + repayment period)

Notes

Leap years (February 29) and varying days in each month (28, 30, 31 days) are automatically reflected in date calculations. While results are accurate, always verify with relevant authorities when using in official documents with legal effect. Especially for legally important date calculations such as contract periods, statute of limitations, visa periods, please get expert review.