Date Calculator
Add/subtract intervals or find differences between two dates.
Select Mode
Choose between calculating the difference between two dates, or adding/subtracting time units from a base date.
Input Parameters
Enter your starting and ending dates, or specify the year, month, week, and day offsets you want to apply.
Adjust Settings
Toggle optional preferences, such as whether to include the end date as an extra inclusive day in the duration.
Get Results
View the calculated duration in weeks, years, and months, or inspect the newly generated destination date.
Your Privacy Matters
All calculations run locally in your browser.
No Server Uploads
No variables or results are sent to our servers.
Auto-Cleared
Your session data is erased upon closing the tab.
Key Capabilities
Real-Time Calculations
Processes date differences and adjustments instantly inside your browser sandbox using JavaScript.
Leap Year Compensation
Correctly accounts for varying month lengths and leap years (366 days) to ensure clinical or billing accuracy.
Two-Way Computation
Enables solving for chronological duration differences as well as project planning deadline offsets.
Comprehensive Metrics
Displays duration answers broken down into years, months, and days, along with a total overall day count.
Zero Server Logging
All inputs are computed locally on your device. Your specific schedules and dates are never uploaded or recorded.