Date Calculator
Calculate the number of days between two dates, or add/subtract days from any date. Useful for project planning, deadline tracking, and event scheduling.
How to Use This Calculator
- Select a Mode: Days Between, Add Days, or Subtract Days.
- Enter the relevant dates and number of days as needed.
- Click Calculate to see the result. The Days Between mode also shows the breakdown by months, weeks, and days.
Formula
Result Date = Start Date ± N days
The calculator accounts for varying month lengths and leap years when computing the difference or adding/subtracting days.
Examples
180 days (5 months, 29 days). Useful for planning a 6-month project timeline.
Result = Jun 13, 2026. Common for 90-day probation periods or warranty claims.
Result = Nov 25, 2026. Useful for calculating cutoff dates for orders or registrations.
Frequently Asked Questions
Does this count business days or calendar days?
This calculator counts all calendar days including weekends and holidays. For business day calculations, use the Business Day Calculator.
Does it handle leap years?
Yes. The calculator correctly accounts for leap years (e.g., Feb 29 in leap years) when computing date differences.
Can I calculate weeks or months?
The Days Between mode shows the breakdown into months, weeks, and remaining days for your convenience.