Date Difference Calculator
Calculate exact difference between two dates in years, months, weeks, days, hours, minutes, seconds, working days, and percentage of year.
Time Unit Equivalents & Business Days
How to Use Date Difference Calculator
- Select your Start Date using the date picker or quick presets (Today, Jan 1, 1 Year Ago).
- Select your End Date (or click Swap Dates to invert direction).
- Optionally check 'Include end day in calculation' if you want both boundaries included.
- Instantly view the total elapsed duration broken down into years, months, days, total weeks, working business days, and hours.
Key Features & Privacy Guarantee
- Exact Gregorian Calendar Math: Accurately handles irregular month lengths (28, 29, 30, 31 days) and leap years.
- Business vs. Weekend Breakdown: Automatically counts working days (Mon-Fri) and weekend off-days (Sat-Sun).
- Multiple Granularities: Outputs difference simultaneously in total days, weeks + remaining days, approximate months, and total hours.
- Interactive Quick Presets: Instant one-click date shortcuts for common year-to-date and anniversary calculations.
- 100% Client-Side Privacy: Calculated in your browser using JavaScript Date APIs without sending dates to any server.
Frequently Asked Questions
How does this calculator calculate months and days between two dates?
The calculator takes the Gregorian calendar start and end dates and computes the difference in full years, remainder full months, and remainder days by borrowing days from the previous month where necessary, accounting for variable 28-31 day month lengths.
What does 'Include end day (+1 day)' mean?
In standard date math (such as subtracting Jan 1 from Jan 2), the difference is 1 day. If you check 'Include end day', both Jan 1 and Jan 2 are counted as full active days, resulting in 2 days.
Does this date difference tool count leap days?
Yes. Leap years (such as 2024, 2028, 2032) with 29 days in February are fully factored into both calendar day totals and year/month breakdowns.