Date Calculator
Use negative numbers to subtract.
This date calculator is for informational purposes. Business day calculations exclude weekends but not public holidays.
What is a Date Difference Calculator?
A date difference calculator computes the exact time between any two dates, expressed in days, weeks, months, and years. It accounts for leap years, varying month lengths, and provides additional breakdowns like business days (weekdays only) and weekend days.
The add/subtract mode lets you add or subtract any combination of years, months, weeks, and days from a starting date to find the resulting date. This is useful for calculating deadlines, due dates, expiration dates, and future events.
How the Date Calculator Works
📅 Difference Mode
- Enter a start date and end date
- Results auto-calculate instantly
- See years, months, days breakdown
- View total days, weeks, business days, weekend days
- Get hours and minutes breakdown
➕ Add/Subtract Mode
- Enter a starting date
- Specify years, months, weeks, or days to add
- Use negative numbers to subtract
- See the resulting date instantly
- View day of week and days from today
Common Uses
Project Planning
Calculate working days between milestones and deadlines.
Contract & Legal Deadlines
Calculate notice periods, filing deadlines, and statute of limitations.
Pregnancy & Due Dates
Calculate expected due dates and weeks of pregnancy.
Travel Planning
Count days until departure or duration of trips.
Event Countdowns
How many days until a wedding, graduation, or holiday.
Shipping Estimates
Calculate business days for delivery timelines.
Frequently Asked Questions
How do I calculate days between two dates?
Enter both dates and the calculator computes instantly, accounting for leap years and varying month lengths.
Does it account for leap years?
Yes. Leap years are correctly handled in all calculations.
Can I calculate business days?
Yes. Business days (Mon–Fri) are shown alongside calendar days. Note: public holidays are not excluded.
Can I add or subtract days?
Yes. Switch to Add/Subtract mode to add or subtract years, months, weeks, or days from any date.
Calendar days vs business days?
Calendar = all days. Business = weekdays only (Mon–Fri). The difference is the weekend count.
How accurate is the calculator?
Accurate to the day. It handles leap years, 28–31 day months, and century boundaries correctly.