Date Calculator: Calculate Days Between Dates, Add or Subtract Days
Calculate the number of days, weeks, months, or years between two dates. Add or subtract days from any date. Find due dates, deadlines, and date differences instantly.
How Date Calculations Work
Date differences are calculated using the Gregorian calendar, accounting for leap years and varying month lengths.
All calculations account for leap years. A leap year occurs every 4 years (divisible by 4), except century years not divisible by 400.
How to Use the Date Calculator
Choose your calculation type
Date difference (between two dates) or date addition/subtraction.
Enter your dates
Use the date pickers or type dates in MM/DD/YYYY format.
Click Calculate
See the result in days, weeks, months, and years.
Real-World Scenario Example
"From January 1, 2026 to December 31, 2026 = 364 days, 52 weeks, 11 months."
Inputs
Result
364 days | 52 weeks | 11 months | 0 years
Important Disclaimer
Date calculations use the proleptic Gregorian calendar. Historical dates before the calendar's adoption (1582) may not reflect the historical calendar system in use at the time.
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