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Free Date Calculator — Add or Subtract Days Between Dates
Calculate days between dates, add or subtract days.
About Date Calculator
Find the exact number of days, weeks, or months between any two dates, or calculate what date falls X days from now (or ago). Useful for project planning, counting down to events, calculating age, tracking subscription periods, or figuring out due dates for invoices and assignments. Works with any date range — past, present, or future.
How to Use Date Calculator
- 1Choose Calculate Duration to find days between two dates, or Add/Subtract to find a future or past date
- 2Select your dates using the date pickers or type them manually
- 3The result shows total days, weeks, months, and years between the dates
- 4Toggle between calendar days and business days (Mon-Fri) mode
When to Use Date Calculator
- ▸Counting days until a wedding, vacation, or deadline
- ▸Calculating project durations and milestone dates
- ▸Determining invoice due dates and payment terms
- ▸Finding the date X business days from now for shipping estimates
Frequently Asked Questions
- Does it account for leap years?
- Yes — the calculator accounts for all leap years, including the special case where century years must be divisible by 400 to be leap years.
- Can I calculate in business days only?
- Yes — switch to business days mode to exclude weekends (Saturday and Sunday) from the calculation, which is useful for project planning and shipping estimates.