Date Difference Calculator
Find the time between two dates in years, months, days, weeks and business days.
What the Date Difference Calculator does
The gap between two dates can be expressed as a plain day count or as calendar years, months and days. Both are shown because they answer different questions — "how many days until" versus "how long ago".
Formula
Total days = End date − Start dateInclusive count adds one to include both endpointsCalendar difference borrows from the preceding month when days go negative
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Start date | date | Yes | — |
| End date | date | Yes | — |
| Count | one of 2 options | Yes | — |
How to use it
- Choose Count.
- Enter Start date and End date.
- Select Calculate.
Worked example
From 1 January 2025 to 14 August 2026.
- Start
- 2025-01-01
- End
- 2026-08-14
590 days, or 1 year 7 months 13 days, including 422 business days.
Frequently asked questions
Should I count both the start and end day?
It depends on the purpose. Hotel nights exclude the checkout day; contract notice periods often include both. Use the toggle to match your situation.