Date Difference Calculator

Find the exact days, weeks, months, and years between two dates. Add or subtract days. Live countdown to any event.

Advanced — Include end date: No · Exclude holidays: No

What is the Date Difference Calculator?

The date difference calculator finds the exact number of days, weeks, months, and years between any two dates. It also counts business days (Monday-Friday) and weekend days separately — useful for project planning, deadlines, legal timelines, and contract terms. All calculation runs in your browser; no dates are sent to any server.

Three modes: Date Difference gives a full breakdown between two dates. Add/Subtract Days computes the resulting date after adding or removing calendar or business days. Countdown shows a live-ticking countdown to any future event.

How to Use the Date Difference Calculator

  1. Choose a mode: Date Difference, Add/Subtract Days, or Countdown.
  2. Enter dates. Use the quick-fill pills to jump to common ranges.
  3. Click Calculate or press Ctrl+Enter.
  4. View total days, weeks, months, years, business days, hours, and minutes.
  5. Open Advanced to include the end date or exclude US holidays from the business day count.

Tips & Use Cases

Count days from today to a future deadline. Calculate business days for project delivery estimates. Find how many days between two historical dates. Use Add/Subtract to find "what date is 90 business days from today?" Use Countdown for product launches, events, or personal milestones. Pair with the Age Calculator for birth-date math, or the Unix Timestamp Converter for epoch-based date work.

Frequently Asked Questions

How do I calculate days between two dates?

Enter a start date and end date in Date Difference mode, then click Calculate. The tool shows total days, weeks, months, years, business days, hours, and minutes.

What are business days?

Business days are weekdays (Monday-Friday), excluding weekends. Enable "Exclude US public holidays" in Advanced for more accurate business day counts.

Can I add days to a date?

Yes. Switch to Add/Subtract mode. Enter a start date and the number of days (positive to add, negative to subtract). Check "business days only" to skip weekends.

How does the countdown work?

Set a target date and optional event name. The countdown updates every second, showing days, hours, minutes, and seconds remaining.

Is this tool free and private?

Yes. Runs entirely in your browser. Your dates are never sent to any server.