Date Difference Calculator
Calculate the exact difference between two dates.
How It Works
- 1
Select your dates
Enter a start date and end date. Toggle 'Countdown mode' to set the start date to today.
- 2
Review the difference
See total days, weeks, months, and full year/month/day breakdown. Toggle 'Exclude weekends' for business days.
- 3
Use for planning
Apply the result to project timelines, legal deadlines, or travel planning.
Calculating Date Differences
Knowing the exact number of days between two dates is essential for project management, legal deadlines, travel planning, and financial calculations like loan interest accrual. Date arithmetic is surprisingly complex due to months of varying lengths (28–31 days), leap years, and the distinction between calendar days and business days. Our calculator handles all of this automatically, correctly accounting for leap years including the century rule (divisible by 100 is not a leap year unless also divisible by 400). It provides results in multiple formats: total calendar days, weeks and remainder days, months and days, and a full year/month/day breakdown. The business day mode counts only weekdays (Monday through Friday), critical for legal notice periods and contractual deadlines.
Frequently Asked Questions
How do I calculate the number of days between two dates?
Enter your start and end dates into the calculator. It automatically computes the total calendar days, weeks with remainder days, months, and a full year/month/day breakdown.
Does the calculator account for leap years?
Yes. The calculator correctly handles leap years, including February 29. A span from January 1, 2024 to January 1, 2025 correctly returns 366 days.
How are business days calculated?
When 'Exclude weekends' is checked, the calculator counts only Monday through Friday. Note that public holidays are not excluded — only Saturdays and Sundays.