Date Calculator
Calculate difference between dates or add/subtract days
Date Difference
Add/Subtract Days
What is Date Calculator?
Time is the most valuable resource, yet it is notoriously hard to calculate in our heads. "What is 45 days from today?" or "How many working days until Christmas?" The **Date Calculator** handles the complex calendar math for you, accounting for leap years, varying month lengths, and weekends.
How to Use Date Calculator
Choose Mode
Select "Difference between dates" or "Add days to date".
Enter Dates
Input start and end dates in the calendar picker.
Calculate
View result in years, months, weeks, and days.
Exclude Weekends
Toggle "Business Days Only" to see working days.
We use standard Gregorian calendar algorithms. **Difference**: Calculates the span between Date A and Date B. **Manipulation**: Adds X days/weeks/months to a base date.
Why Use This Tool?
**Accuracy**: No more counting on fingers or miscalculating leap years. **Planning**: Essential for project managers to set realistic deadlines. **Compliance**: HRs use it to calculate notice periods and leave balances exactly.
Who Is This For?
**Visa Rules**: Calculating the exact "90 days out of 180" for Schengen visas. **Pregnancy**: Estimating due dates (40 weeks rule).
Behind the Technology
JavaScript Date object manipulation with custom logic for business day filtering.
Tips for Best Results
Use the 'Working Days' toggle to get a realistic project timeline.
Remember that end-dates are often inclusive in contracts but exclusive in code.
Use 'Add Days' to quickly find the date of your 100-day challenge finish line.