Date Difference Calculator
Pick two dates to find the number of days between them.
Calculator
Use the Date Difference Calculator
Result
—
Formula
end − start (in days)
Step-by-step
- 1
Pick both dates
Use YYYY-MM-DD format.
- 2
Read the gap
Whole days between the dates.
Worked example
Example input: start: 2026-01-01, end: 2026-01-31
Result: 30
Related tools
- Age Calculator
Years since a birthdate.
- Deadline Calculator
Days until a target date.
Frequently asked questions
Does the end date count as a full day?
No — the gap counts up to, but not including, the end date. January 1 to January 31 of the same year is 30 days, not 31.
What happens if the start date is after the end date?
Subtraction simply runs backwards and returns a negative number of days. Swap the two dates to get the positive count.
Are leap years handled?
Yes — the calendar arithmetic counts real days, so February 29 counts automatically whenever a leap day falls inside the range.
How are leap years handled?
The calculation counts true calendar days, so a February 29 inside your range is included whenever one appears. Leap years come every 4 years, except century years not divisible by 400 — 2000 counted, 1900 did not.