Date Difference Calculator
Calculate the exact difference between two dates. Get detailed breakdowns in years, months, days, and more with our comprehensive date difference calculator.
Date Difference Calculator
Calculate the exact difference between two dates
Common Use Cases:
- • Calculate age or time since an event
- • Project planning and timeline calculation
- • Anniversary and milestone tracking
- • Contract duration and expiration dates
How to Use the Date Difference Calculator
Enter Start Date: Select the beginning date for your calculation.
Enter End Date: Select the ending date for your calculation.
Include End Date: Choose whether to include the end date in your calculation.
Get Results: View the comprehensive breakdown of time difference.
Common Use Cases
Age Calculation
Calculate someone's exact age in years, months, and days from their birth date to today.
Project Duration
Determine the length of a project from start date to end date, including weekday calculations.
Anniversary Tracking
Find out how many days, months, or years have passed since a special event or anniversary.
Contract Duration
Calculate the exact duration of contracts, subscriptions, or agreements between two dates.
Date Calculation Tips
Including the End Date
Decide whether to include the end date in your count. For event duration, include both dates (Jan 1 to Jan 3 = 3 days). For "days until" calculations, exclude the end date (Jan 1 to Jan 3 = 2 days). Contract terms often include both start and end dates.
Leap Year Considerations
The calculator automatically accounts for leap years when calculating date differences. Leap years occur every 4 years (except century years not divisible by 400). February has 29 days in leap years, affecting any calculations spanning that period.
Time Zone Effects
Date calculators work with calendar dates, not specific times. If you're calculating across time zones, use the calendar date in the relevant location. For precise time tracking including hours and minutes, use a time duration calculator instead.
Business vs Calendar Days
This calculator shows calendar days (including weekends and holidays). For business day calculations that exclude weekends and holidays, use our Business Days Calculator. Contracts and deadlines often specify which type to use.