Method and assumptions
Calculate the calendar distance and weekdays between two dates, or add and subtract a non-negative whole number of days from a starting date.
Date Calculator
Count days between dates or add and subtract time.
Reviewed: 2026-07-21
How to use it
- Choose date difference or date addition.
- Enter the starting date and requested values.
- Review the calendar result and summary.
When it helps
- Planning a deadline or project
- Counting a contract or travel period
- Finding the date a number of days from now
How to verify the result
Check input units and reference dates first. For an important decision, compare the result with an official source or original document. A rounded display can differ slightly from the underlying value.
Frequently asked questions
Does the difference include the start date?
No. This tool treats the starting point as day zero. Add one to the result if you need to count both endpoints.
Are leap years handled automatically?
Yes. Standard calendar arithmetic accounts for February 29 in leap years.
Can time zones change the answer?
The tool calculates the entered calendar dates without converting a time or time zone, which avoids common date shifts.